--- contrib/tzdata/Makefile.orig
+++ contrib/tzdata/Makefile
@@ -22,13 +22,13 @@
 #	DATAFORM=	main
 # To wait even longer for new features, use:
 #	DATAFORM=	rearguard
+# Rearguard users might also want "ZFLAGS = -b fat"; see below.
 DATAFORM=		main
 
 # Change the line below for your timezone (after finding the one you want in
 # one of the $(TDATA) source files, or adding it to a source file).
 # Alternatively, if you discover you've got the wrong timezone, you can just
-#	zic -l rightzone
-# to correct things.
+# 'zic -l -' to remove it, or 'zic -l rightzone' to change it.
 # Use the command
 #	make zonenames
 # to get a list of the values you can use for LOCALTIME.
@@ -37,25 +37,13 @@
 
 # The POSIXRULES macro controls interpretation of nonstandard and obsolete
 # POSIX-like TZ settings like TZ='EET-2EEST' that lack DST transition rules.
-# In the reference implementation, if you want something other than Eastern
-# United States time as a template for handling these settings, you can
-# change the line below (after finding the timezone you want in the
-# one of the $(TDATA) source files, or adding it to a source file).
-# A setting like TZ='EET-2EEST' is supposed to use the rules in the
-# template file to determine "spring forward" and "fall back" days and
-# times; the environment variable itself specifies UT offsets of standard and
-# daylight saving time.
-# Alternatively, if you discover you've got the wrong timezone, you can just
-#	zic -p rightzone
-# to correct things.
-# Use the command
-#	make zonenames
-# to get a list of the values you can use for POSIXRULES.
+# Such a setting uses the rules in a template file to determine
+# "spring forward" and "fall back" days and times; the environment
+# variable itself specifies UT offsets of standard and daylight saving time.
 #
-# If POSIXRULES is empty, no template is installed; this is the intended
-# future default for POSIXRULES.
+# If POSIXRULES is '-', no template is installed; this is the default.
 #
-# Nonempty POSIXRULES is obsolete and should not be relied on, because:
+# Any other value for POSIXRULES is obsolete and should not be relied on, as:
 # * It does not work correctly in popular implementations such as GNU/Linux.
 # * It does not work in the tzdb implementation for timestamps after 2037.
 # * It is incompatible with 'zic -b slim' if POSIXRULES specifies transitions
@@ -62,8 +50,17 @@
 #   at standard time or UT rather than at local time.
 # In short, software should avoid ruleless settings like TZ='EET-2EEST'
 # and so should not depend on the value of POSIXRULES.
+#
+# If, despite the above, you want a template for handling these settings,
+# you can change the line below (after finding the timezone you want in the
+# one of the $(TDATA) source files, or adding it to a source file).
+# Alternatively, if you discover you've got the wrong timezone, you can just
+# 'zic -p -' to remove it, or 'zic -p rightzone' to change it.
+# Use the command
+#	make zonenames
+# to get a list of the values you can use for POSIXRULES.
 
-POSIXRULES=	America/New_York
+POSIXRULES=	-
 
 # Also see TZDEFRULESTRING below, which takes effect only
 # if the time zone files cannot be accessed.
@@ -172,9 +169,6 @@
 
 # For backward-compatibility links for old zone names, use
 #	BACKWARD=	backward
-# If you also want the link US/Pacific-New, even though it is confusing
-# and is planned to be removed from the database eventually, use
-#	BACKWARD=	backward pacificnew
 # To omit these links, use
 #	BACKWARD=
 
@@ -192,10 +186,6 @@
 
 UTF8_LOCALE=	en_US.utf8
 
-# Since "." may not be in PATH...
-
-YEARISTYPE=	./yearistype
-
 # Non-default libraries needed to link.
 LDLIBS=
 
@@ -253,13 +243,12 @@
 #	other than simply getting garbage data
 #  -DUSE_LTZ=0 to build zdump with the system time zone library
 #	Also set TZDOBJS=zdump.o and CHECK_TIME_T_ALTERNATIVES= below.
-#  -DZIC_BLOAT_DEFAULT=\"slim\" to default zic's -b option to "slim", and
-#	similarly for "fat".  Fat TZif files work around incompatibilities
+#  -DZIC_BLOAT_DEFAULT=\"fat\" to default zic's -b option to "fat", and
+#	similarly for "slim".  Fat TZif files work around incompatibilities
 #	and bugs in some TZif readers, notably readers that mishandle 64-bit
 #	data in TZif files.  Slim TZif files are more efficient and do not
 #	work around these incompatibilities and bugs.  If not given, the
-#	current default is "fat" but this is intended to change as readers
-#	requiring fat files often mishandle timestamps after 2037 anyway.
+#	default is "slim".
 #  -DZIC_MAX_ABBR_LEN_WO_WARN=3
 #	(or some other number) to set the maximum time zone abbreviation length
 #	that zic will accept without a warning (the default is 6)
@@ -333,9 +322,8 @@
 # add
 #	-DSTD_INSPIRED
 # to the end of the "CFLAGS=" line.  This arranges for the functions
-# "tzsetwall", "offtime", "timelocal", "timegm", "timeoff",
+# "offtime", "timelocal", "timegm", "timeoff",
 # "posix2time", and "time2posix" to be added to the time conversion library.
-# "tzsetwall" is deprecated and is intended to be removed soon; see NEWS.
 # "offtime" is like "gmtime" except that it accepts a second (long) argument
 # that gives an offset to add to the time_t when converting it.
 # "timelocal" is equivalent to "mktime".
@@ -395,7 +383,7 @@
 
 # To shrink the size of installed TZif files,
 # append "-r @N" to omit data before N-seconds-after-the-Epoch.
-# You can also append "-b slim" if that is not already the default;
+# To grow the files and work around older application bugs, append "-b fat";
 # see ZIC_BLOAT_DEFAULT above.
 # See the zic man page for more about -b and -r.
 ZFLAGS=
@@ -424,26 +412,6 @@
 # Name of GNU Privacy Guard <https://gnupg.org/>, used to sign distributions.
 GPG=		gpg
 
-# The path where SGML DTDs are kept and the catalog file(s) to use when
-# validating HTML 4.01.  The default should work on both Debian and Red Hat.
-SGML_TOPDIR= /usr
-SGML_DTDDIR= $(SGML_TOPDIR)/share/xml/w3c-sgml-lib/schema/dtd
-SGML_SEARCH_PATH= $(SGML_DTDDIR)/REC-html401-19991224
-SGML_CATALOG_FILES= \
-  $(SGML_TOPDIR)/share/doc/w3-recs/html/www.w3.org/TR/1999/REC-html401-19991224/HTML4.cat:$(SGML_TOPDIR)/share/sgml/html/4.01/HTML4.cat
-
-# The name, arguments and environment of a program to validate HTML 4.01.
-# See <http://openjade.sourceforge.net/doc/> for a validator, and
-# <https://validator.w3.org/source/> for a validation library.
-# Set VALIDATE=':' if you do not have such a program.
-VALIDATE = nsgmls
-VALIDATE_FLAGS = -s -B -wall -wno-unused-param
-VALIDATE_ENV = \
-  SGML_CATALOG_FILES='$(SGML_CATALOG_FILES)' \
-  SGML_SEARCH_PATH='$(SGML_SEARCH_PATH)' \
-  SP_CHARSET_FIXED=YES \
-  SP_ENCODING=UTF-8
-
 # This expensive test requires USE_LTZ.
 # To suppress it, define this macro to be empty.
 CHECK_TIME_T_ALTERNATIVES = check_time_t_alternatives
@@ -538,8 +506,8 @@
 PRIMARY_YDATA=	africa antarctica asia australasia \
 		europe northamerica southamerica
 YDATA=		$(PRIMARY_YDATA) etcetera
-NDATA=		systemv factory
-TDATA_TO_CHECK=	$(YDATA) $(NDATA) backward pacificnew
+NDATA=		factory
+TDATA_TO_CHECK=	$(YDATA) $(NDATA) backward
 TDATA=		$(YDATA) $(NDATA) $(BACKWARD)
 ZONETABLES=	zone1970.tab zone.tab
 TABDATA=	iso3166.tab $(TZDATA_TEXT) $(ZONETABLES)
@@ -547,7 +515,7 @@
 TZDATA_ZI_DEPS=	ziguard.awk zishrink.awk version $(TDATA) $(PACKRATDATA)
 DSTDATA_ZI_DEPS= ziguard.awk $(TDATA) $(PACKRATDATA)
 DATA=		$(TDATA_TO_CHECK) backzone iso3166.tab leap-seconds.list \
-			leapseconds yearistype.sh $(ZONETABLES)
+			leapseconds $(ZONETABLES)
 AWK_SCRIPTS=	checklinks.awk checktab.awk leapseconds.awk \
 			ziguard.awk zishrink.awk
 MISC=		$(AWK_SCRIPTS) zoneinfo2tdf.pl
@@ -573,12 +541,10 @@
 		etcetera europe factory iso3166.tab \
 		leap-seconds.list leapseconds.awk localtime.c \
 		newctime.3 newstrftime.3 newtzset.3 northamerica \
-		pacificnew private.h \
-		southamerica strftime.c systemv theory.html \
+		private.h southamerica strftime.c theory.html \
 		time2posix.3 tz-art.html tz-how-to.html tz-link.html \
 		tzfile.5 tzfile.h tzselect.8 tzselect.ksh \
-		workman.sh yearistype.sh \
-		zdump.8 zdump.c zic.8 zic.c \
+		workman.sh zdump.8 zdump.c zic.8 zic.c \
 		ziguard.awk zishrink.awk \
 		zone.tab zone1970.tab zoneinfo2tdf.pl
 
@@ -587,7 +553,7 @@
 
 SHELL=		/bin/sh
 
-all:		tzselect yearistype zic zdump libtz.a $(TABDATA) \
+all:		tzselect zic zdump libtz.a $(TABDATA) \
 		  vanguard.zi main.zi rearguard.zi
 
 ALL:		all date $(ENCHILADA)
@@ -657,10 +623,6 @@
 zic:		$(TZCOBJS)
 		$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZCOBJS) $(LDLIBS)
 
-yearistype:	yearistype.sh
-		cp yearistype.sh yearistype
-		chmod +x yearistype
-
 leapseconds:	$(LEAP_DEPS)
 		$(AWK) -v EXPIRES_LINE=$(EXPIRES_LINE) \
 		  -f leapseconds.awk leap-seconds.list >$@.out
@@ -675,10 +637,9 @@
  PACKRATDATA='$(PACKRATDATA)' \
  TZDEFAULT='$(TZDEFAULT)' \
  TZDIR='$(TZDIR)' \
- YEARISTYPE='$(YEARISTYPE)' \
  ZIC='$(ZIC)'
 
-INSTALL_DATA_DEPS = zic leapseconds yearistype tzdata.zi
+INSTALL_DATA_DEPS = zic leapseconds tzdata.zi
 
 # 'make install_data' installs one set of TZif files.
 install_data: $(INSTALL_DATA_DEPS)
@@ -793,7 +754,7 @@
 		! grep -Env $(SAFE_LINE)'|^UNUSUAL_OK_'$(OK_CHAR)'*$$' \
 			Makefile && \
 		! grep -Env $(SAFE_SHARP_LINE) $(TDATA_TO_CHECK) backzone \
-			leapseconds yearistype.sh zone.tab && \
+			leapseconds zone.tab && \
 		! grep -Env $(OK_LINE) $(ENCHILADA); \
 	}
 	touch $@
@@ -845,15 +806,13 @@
 check_web:	$(CHECK_WEB_PAGES)
 check_theory.html: theory.html
 check_tz-art.html: tz-art.html
+check_tz-how-to.html: tz-how-to.html
 check_tz-link.html: tz-link.html
-check_theory.html check_tz-art.html check_tz-link.html:
+check_theory.html check_tz-art.html check_tz-how-to.html check_tz-link.html:
 		$(CURL) -sS --url https://validator.w3.org/nu/ -F out=gnu \
 		    -F file=@$$(expr $@ : 'check_\(.*\)') -o $@.out && \
 		  test ! -s $@.out || { cat $@.out; exit 1; }
 		mv $@.out $@
-check_tz-how-to.html: tz-how-to.html
-		$(VALIDATE_ENV) $(VALIDATE) $(VALIDATE_FLAGS) tz-how-to.html
-		touch $@
 
 # Check that zishrink.awk does not alter the data, and that ziguard.awk
 # preserves main-format data.
@@ -883,7 +842,7 @@
 		rm -fr check_*.dir
 		rm -f *.o *.out $(TIME_T_ALTERNATIVES) \
 		  check_* core typecheck_* \
-		  date tzselect version.h zdump zic yearistype libtz.a
+		  date tzselect version.h zdump zic libtz.a
 clean:		clean_misc
 		rm -fr *.dir tzdb-*/
 		rm -f *.zi $(TZS_NEW)
@@ -1063,10 +1022,14 @@
 		done
 		sed '1s/$$/-rearguard/' \
 		  <version >tzdata$(VERSION)-rearguard.dir/version
+		: The dummy pacificnew pacifies TZUpdater 2.3.1 and earlier.
+		TZ=UTC0 touch -mt 202010122253.00 \
+		  tzdata$(VERSION)-rearguard.dir/pacificnew
 		touch -cmr version tzdata$(VERSION)-rearguard.dir/version
 		LC_ALL=C && export LC_ALL && \
 		  (cd tzdata$(VERSION)-rearguard.dir && \
-		   tar $(TARFLAGS) -cf - $(COMMON) $(DATA) $(MISC) | \
+		   tar $(TARFLAGS) -cf - \
+			$(COMMON) $(DATA) $(MISC) pacificnew | \
 		     gzip $(GZIPFLAGS)) >$@.out
 		mv $@.out $@
 
--- contrib/tzdata/NEWS.orig
+++ contrib/tzdata/NEWS
@@ -1,5 +1,114 @@
 News for the tz database
 
+Release 2020d - 2020-10-21 11:24:13 -0700
+
+  Briefly:
+    Palestine ends DST earlier than predicted, on 2020-10-24.
+
+  Changes to past and future timestamps
+
+    Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
+    as previously predicted (thanks to Sharef Mustafa.)  Its
+    2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
+    Thorsen.)  Its 2015-10-23 transition was at 01:00 not 00:00, and
+    its spring 2020 transition was on March 28 at 00:00, not March 27
+    (thanks to Pierre Cashon.)  This affects Asia/Gaza and
+    Asia/Hebron.  Assume future spring and fall transitions will be on
+    the Saturday preceding the last Sunday of March and October,
+    respectively.
+
+
+Release 2020c - 2020-10-16 11:15:53 -0700
+
+  Briefly:
+    Fiji starts DST later than usual, on 2020-12-20.
+
+  Changes to future timestamps
+
+    Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
+    previously predicted.  DST will still end on 2021-01-17.
+    (Thanks to Raymond Kumar and Alan Mintz.)  Assume for now that
+    the later-than-usual start date is a one-time departure from the
+    recent pattern.
+
+  Changes to build procedure
+
+    Rearguard tarballs now contain an empty file pacificnew.
+    Some older downstream software expects this file to exist.
+    (Problem reported by Mike Cullinan.)
+
+
+Release 2020b - 2020-10-06 18:35:04 -0700
+
+  Briefly:
+    Revised predictions for Morocco's changes starting in 2023.
+    Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
+    Macquarie Island has stayed in sync with Tasmania since 2011.
+    Casey, Antarctica is at +08 in winter and +11 in summer.
+    zic no longer supports -y, nor the TYPE field of Rules.
+
+  Changes to future timestamps
+
+    Morocco's spring-forward after Ramadan is now predicted to occur
+    no sooner than two days after Ramadan, instead of one day.
+    (Thanks to Milamber.)  The first altered prediction is for 2023,
+    now predicted to spring-forward on April 30 instead of April 23.
+
+  Changes to past and future timestamps
+
+   Casey Station, Antarctica has been using +08 in winter and +11 in
+   summer since 2018.  The most recent transition from +08 to +11 was
+   2020-10-04 00:01.  Also, Macquarie Island has been staying in
+   sync with Tasmania since 2011.  (Thanks to Steffen Thorsen.)
+
+  Changes to past and future time zone abbreviations and DST flags
+
+    Canada's Yukon, represented by America/Whitehorse and
+    America/Dawson, changes its time zone rules from -08/-07 to
+    permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
+    This change affects only the time zone abbreviation (MST vs PDT)
+    and daylight saving flag for the period between the two dates.
+    (Thanks to Andrew G. Smith.)
+
+  Changes to past timestamps
+
+    Correct several transitions for Hungary for 1918/1983.
+    For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
+    (Thanks to Géza Nyáry.)  Also, the 1890 transition to standard
+    time was on 11-01, not 10-01 (thanks to Michael Deckers).
+
+    The 1891 French transition was on March 16, not March 15.  The
+    1911-03-11 French transition was at midnight, not a minute later.
+    Monaco's transitions were on 1892-06-01 and 1911-03-29, not
+    1891-03-15 and 1911-03-11.  (Thanks to Michael Deckers.)
+
+  Changes to code
+
+    Support for zic's long-obsolete '-y YEARISTYPE' option has been
+    removed and, with it, so has support for the TYPE field in Rule
+    lines, which is now reserved for compatibility with earlier zic.
+    These features were previously deprecated in release 2015f.
+    (Thanks to Tim Parenti.)
+
+    zic now defaults to '-b slim' instead of to '-b fat'.
+
+    zic's new '-l -' and '-p -' options uninstall any existing
+    localtime and posixrules files, respectively.
+
+    The undocumented and ineffective tzsetwall function has been
+    removed.
+
+  Changes to build procedure
+
+    The Makefile now defaults POSIXRULES to '-', so the posixrules
+    feature (obsolete as of 2019b) is no longer installed by default.
+
+  Changes to documentation and commentary
+
+    The long-obsolete files pacificnew, systemv, and yearistype.sh have
+    been removed from the distribution.  (Thanks to Tim Parenti.)
+
+
 Release 2020a - 2020-04-23 16:03:47 -0700
 
   Briefly:
--- contrib/tzdata/README.orig
+++ contrib/tzdata/README
@@ -20,6 +20,8 @@
 	make TOPDIR=$HOME/tzdir install
 	$HOME/tzdir/usr/bin/zdump -v America/Los_Angeles
 
+See the file tz-how-to.html for examples of how to read the data files.
+
 This database of historical local time information has several goals:
 
  * Provide a compendium of data about the history of civil time that
--- contrib/tzdata/africa.orig
+++ contrib/tzdata/africa
@@ -64,7 +64,7 @@
 # Corrections are welcome.
 
 # Algeria
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Algeria	1916	only	-	Jun	14	23:00s	1:00	S
 Rule	Algeria	1916	1919	-	Oct	Sun>=1	23:00s	0	-
 Rule	Algeria	1917	only	-	Mar	24	23:00s	1:00	S
@@ -87,10 +87,9 @@
 Rule	Algeria	1978	only	-	Sep	22	 3:00	0	-
 Rule	Algeria	1980	only	-	Apr	25	 0:00	1:00	S
 Rule	Algeria	1980	only	-	Oct	31	 2:00	0	-
-# Shanks & Pottenger give 0:09:20 for Paris Mean Time; go with Howse's
-# more precise 0:09:21.
+# See Europe/Paris for PMT-related transitions.
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
-Zone	Africa/Algiers	0:12:12 -	LMT	1891 Mar 15  0:01
+Zone	Africa/Algiers	0:12:12 -	LMT	1891 Mar 16
 			0:09:21	-	PMT	1911 Mar 11 # Paris Mean Time
 			0:00	Algeria	WE%sT	1940 Feb 25  2:00
 			1:00	Algeria	CE%sT	1946 Oct  7
@@ -176,7 +175,7 @@
 # Egypt was mean noon at the Great Pyramid, 2:04:30.5, but apparently this
 # did not apply to Cairo, Alexandria, or Port Said.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Egypt	1940	only	-	Jul	15	0:00	1:00	S
 Rule	Egypt	1940	only	-	Oct	 1	0:00	0	-
 Rule	Egypt	1941	only	-	Apr	15	0:00	1:00	S
@@ -411,7 +410,7 @@
 # now Ghana observed different DST regimes in different years.  For
 # lack of better info, use Shanks except treat the minus sign as a
 # typo, and assume DST started in 1920 not 1936.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Ghana	1920	1942	-	Sep	 1	0:00	0:20	-
 Rule	Ghana	1920	1942	-	Dec	31	0:00	0	-
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
@@ -501,7 +500,7 @@
 # From Paul Eggert (2013-10-25):
 # For now, assume they're reverting to the pre-2012 rules of permanent UT +02.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Libya	1951	only	-	Oct	14	2:00	1:00	S
 Rule	Libya	1952	only	-	Jan	 1	0:00	0	-
 Rule	Libya	1953	only	-	Oct	 9	2:00	1:00	S
@@ -624,7 +623,7 @@
 # "The trial ended on March 29, 2009, when the clocks moved back by one hour
 # at 2am (or 02:00) local time..."
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule Mauritius	1982	only	-	Oct	10	0:00	1:00	-
 Rule Mauritius	1983	only	-	Mar	21	0:00	0	-
 Rule Mauritius	2008	only	-	Oct	lastSun	2:00	1:00	-
@@ -875,17 +874,30 @@
 # https://maroc-diplomatique.net/maroc-le-retour-a-lheure-gmt-est-prevu-dimanche-prochain/
 # http://aujourdhui.ma/actualite/gmt1-retour-a-lheure-normale-dimanche-prochain-1
 #
-# From Paul Eggert (2020-04-14):
+# From Milamber (2020-05-31)
+# In Morocco (where I live), the end of Ramadan (Arabic month) is followed by
+# the Eid al-Fitr, and concretely it's 1 or 2 day offs for the people (with
+# traditional visiting of family, big lunches/dinners, etc.).  So for this
+# year the astronomical calculations don't include the following 2 days off in
+# the calc.  These 2 days fall in a Sunday/Monday, so it's not acceptable by
+# people to have a time shift during these 2 days off.  Perhaps you can modify
+# the (predicted) rules for next years: if the end of Ramadan is a (probable)
+# Friday or Saturday (and so the 2 days off are on a weekend), the next time
+# shift will be the next weekend.
+#
+# From Paul Eggert (2020-05-31):
 # For now, guess that in the future Morocco will fall back at 03:00
 # the last Sunday before Ramadan, and spring forward at 02:00 the
-# first Sunday after the day after Ramadan.  To implement this,
-# transition dates for 2021 through 2087 were determined by running
-# the following program under GNU Emacs 26.3.
-# (let ((islamic-year 1442))
+# first Sunday after two days after Ramadan.  To implement this,
+# transition dates and times for 2019 through 2087 were determined by
+# running the following program under GNU Emacs 26.3.  (This algorithm
+# also produces the correct transition dates for 2016 through 2018,
+# though the times differ due to Morocco's time zone change in 2018.)
+# (let ((islamic-year 1440))
 #   (require 'cal-islam)
 #   (while (< islamic-year 1511)
 #     (let ((a (calendar-islamic-to-absolute (list 9 1 islamic-year)))
-#           (b (1+ (calendar-islamic-to-absolute (list 10 1 islamic-year))))
+#           (b (+ 2 (calendar-islamic-to-absolute (list 10 1 islamic-year))))
 #           (sunday 0))
 #       (while (/= sunday (mod (setq a (1- a)) 7)))
 #       (while (/= sunday (mod b 7))
@@ -900,7 +912,7 @@
 #         (car (cdr (cdr b))) (calendar-month-name (car b) t) (car (cdr b)))))
 #     (setq islamic-year (+ 1 islamic-year))))
 
-# RULE	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Morocco	1939	only	-	Sep	12	 0:00	1:00	-
 Rule	Morocco	1939	only	-	Nov	19	 0:00	0	-
 Rule	Morocco	1940	only	-	Feb	25	 0:00	1:00	-
@@ -951,7 +963,7 @@
 Rule	Morocco	2022	only	-	Mar	27	 3:00	-1:00	-
 Rule	Morocco	2022	only	-	May	 8	 2:00	0	-
 Rule	Morocco	2023	only	-	Mar	19	 3:00	-1:00	-
-Rule	Morocco	2023	only	-	Apr	23	 2:00	0	-
+Rule	Morocco	2023	only	-	Apr	30	 2:00	0	-
 Rule	Morocco	2024	only	-	Mar	10	 3:00	-1:00	-
 Rule	Morocco	2024	only	-	Apr	14	 2:00	0	-
 Rule	Morocco	2025	only	-	Feb	23	 3:00	-1:00	-
@@ -967,7 +979,7 @@
 Rule	Morocco	2029	only	-	Dec	30	 3:00	-1:00	-
 Rule	Morocco	2030	only	-	Feb	10	 2:00	0	-
 Rule	Morocco	2030	only	-	Dec	22	 3:00	-1:00	-
-Rule	Morocco	2031	only	-	Jan	26	 2:00	0	-
+Rule	Morocco	2031	only	-	Feb	 2	 2:00	0	-
 Rule	Morocco	2031	only	-	Dec	14	 3:00	-1:00	-
 Rule	Morocco	2032	only	-	Jan	18	 2:00	0	-
 Rule	Morocco	2032	only	-	Nov	28	 3:00	-1:00	-
@@ -983,7 +995,7 @@
 Rule	Morocco	2037	only	-	Oct	 4	 3:00	-1:00	-
 Rule	Morocco	2037	only	-	Nov	15	 2:00	0	-
 Rule	Morocco	2038	only	-	Sep	26	 3:00	-1:00	-
-Rule	Morocco	2038	only	-	Oct	31	 2:00	0	-
+Rule	Morocco	2038	only	-	Nov	 7	 2:00	0	-
 Rule	Morocco	2039	only	-	Sep	18	 3:00	-1:00	-
 Rule	Morocco	2039	only	-	Oct	23	 2:00	0	-
 Rule	Morocco	2040	only	-	Sep	 2	 3:00	-1:00	-
@@ -999,7 +1011,7 @@
 Rule	Morocco	2045	only	-	Jul	 9	 3:00	-1:00	-
 Rule	Morocco	2045	only	-	Aug	20	 2:00	0	-
 Rule	Morocco	2046	only	-	Jul	 1	 3:00	-1:00	-
-Rule	Morocco	2046	only	-	Aug	 5	 2:00	0	-
+Rule	Morocco	2046	only	-	Aug	12	 2:00	0	-
 Rule	Morocco	2047	only	-	Jun	23	 3:00	-1:00	-
 Rule	Morocco	2047	only	-	Jul	28	 2:00	0	-
 Rule	Morocco	2048	only	-	Jun	 7	 3:00	-1:00	-
@@ -1015,7 +1027,7 @@
 Rule	Morocco	2053	only	-	Apr	13	 3:00	-1:00	-
 Rule	Morocco	2053	only	-	May	25	 2:00	0	-
 Rule	Morocco	2054	only	-	Apr	 5	 3:00	-1:00	-
-Rule	Morocco	2054	only	-	May	10	 2:00	0	-
+Rule	Morocco	2054	only	-	May	17	 2:00	0	-
 Rule	Morocco	2055	only	-	Mar	28	 3:00	-1:00	-
 Rule	Morocco	2055	only	-	May	 2	 2:00	0	-
 Rule	Morocco	2056	only	-	Mar	12	 3:00	-1:00	-
@@ -1031,7 +1043,7 @@
 Rule	Morocco	2061	only	-	Jan	16	 3:00	-1:00	-
 Rule	Morocco	2061	only	-	Feb	27	 2:00	0	-
 Rule	Morocco	2062	only	-	Jan	 8	 3:00	-1:00	-
-Rule	Morocco	2062	only	-	Feb	12	 2:00	0	-
+Rule	Morocco	2062	only	-	Feb	19	 2:00	0	-
 Rule	Morocco	2062	only	-	Dec	31	 3:00	-1:00	-
 Rule	Morocco	2063	only	-	Feb	 4	 2:00	0	-
 Rule	Morocco	2063	only	-	Dec	16	 3:00	-1:00	-
@@ -1047,7 +1059,7 @@
 Rule	Morocco	2068	only	-	Oct	21	 3:00	-1:00	-
 Rule	Morocco	2068	only	-	Dec	 2	 2:00	0	-
 Rule	Morocco	2069	only	-	Oct	13	 3:00	-1:00	-
-Rule	Morocco	2069	only	-	Nov	17	 2:00	0	-
+Rule	Morocco	2069	only	-	Nov	24	 2:00	0	-
 Rule	Morocco	2070	only	-	Oct	 5	 3:00	-1:00	-
 Rule	Morocco	2070	only	-	Nov	 9	 2:00	0	-
 Rule	Morocco	2071	only	-	Sep	20	 3:00	-1:00	-
@@ -1063,7 +1075,7 @@
 Rule	Morocco	2076	only	-	Jul	26	 3:00	-1:00	-
 Rule	Morocco	2076	only	-	Sep	 6	 2:00	0	-
 Rule	Morocco	2077	only	-	Jul	18	 3:00	-1:00	-
-Rule	Morocco	2077	only	-	Aug	22	 2:00	0	-
+Rule	Morocco	2077	only	-	Aug	29	 2:00	0	-
 Rule	Morocco	2078	only	-	Jul	10	 3:00	-1:00	-
 Rule	Morocco	2078	only	-	Aug	14	 2:00	0	-
 Rule	Morocco	2079	only	-	Jun	25	 3:00	-1:00	-
@@ -1073,13 +1085,13 @@
 Rule	Morocco	2081	only	-	Jun	 1	 3:00	-1:00	-
 Rule	Morocco	2081	only	-	Jul	13	 2:00	0	-
 Rule	Morocco	2082	only	-	May	24	 3:00	-1:00	-
-Rule	Morocco	2082	only	-	Jun	28	 2:00	0	-
+Rule	Morocco	2082	only	-	Jul	 5	 2:00	0	-
 Rule	Morocco	2083	only	-	May	16	 3:00	-1:00	-
 Rule	Morocco	2083	only	-	Jun	20	 2:00	0	-
 Rule	Morocco	2084	only	-	Apr	30	 3:00	-1:00	-
 Rule	Morocco	2084	only	-	Jun	11	 2:00	0	-
 Rule	Morocco	2085	only	-	Apr	22	 3:00	-1:00	-
-Rule	Morocco	2085	only	-	May	27	 2:00	0	-
+Rule	Morocco	2085	only	-	Jun	 3	 2:00	0	-
 Rule	Morocco	2086	only	-	Apr	14	 3:00	-1:00	-
 Rule	Morocco	2086	only	-	May	19	 2:00	0	-
 Rule	Morocco	2087	only	-	Mar	30	 3:00	-1:00	-
@@ -1180,7 +1192,7 @@
 # Use plain "WAT" and "CAT" for the time zone abbreviations, to be compatible
 # with Namibia's neighbors.
 
-# RULE	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 # Vanguard section, for zic and other parsers that support negative DST.
 Rule	Namibia	1994	only	-	Mar	21	0:00	-1:00	WAT
 Rule	Namibia	1994	2017	-	Sep	Sun>=1	2:00	0	CAT
@@ -1303,7 +1315,7 @@
 # See Africa/Nairobi.
 
 # South Africa
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	SA	1942	1943	-	Sep	Sun>=15	2:00	1:00	-
 Rule	SA	1943	1944	-	Mar	Sun>=15	2:00	0	-
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
@@ -1336,7 +1348,7 @@
 # Abdalla of NTC, archived at:
 # https://mm.icann.org/pipermail/tz/2017-October/025333.html
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Sudan	1970	only	-	May	 1	0:00	1:00	S
 Rule	Sudan	1970	1985	-	Oct	15	0:00	0	-
 Rule	Sudan	1971	only	-	Apr	30	0:00	1:00	S
@@ -1424,7 +1436,7 @@
 # http://www.almadenahnews.com/newss/news.php?c=118&id=38036
 # http://www.worldtimezone.com/dst_news/dst_news_tunis02.html
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Tunisia	1939	only	-	Apr	15	23:00s	1:00	S
 Rule	Tunisia	1939	only	-	Nov	18	23:00s	0	-
 Rule	Tunisia	1940	only	-	Feb	25	23:00s	1:00	S
@@ -1451,9 +1463,7 @@
 Rule	Tunisia	2006	2008	-	Mar	lastSun	 2:00s	1:00	S
 Rule	Tunisia	2006	2008	-	Oct	lastSun	 2:00s	0	-
 
-# Shanks & Pottenger give 0:09:20 for Paris Mean Time; go with Howse's
-# more precise 0:09:21.
-# Shanks & Pottenger say the 1911 switch was on Mar 9; go with Howse's Mar 11.
+# See Europe/Paris for PMT-related transitions.
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Tunis	0:40:44 -	LMT	1881 May 12
 			0:09:21	-	PMT	1911 Mar 11 # Paris Mean Time
--- contrib/tzdata/antarctica.orig
+++ contrib/tzdata/antarctica
@@ -70,15 +70,30 @@
 # Australian Antarctica Division informed us that Casey changed time
 # zone to UTC+11 in "the morning of 22nd October 2016".
 
+# From Steffen Thorsen (2020-10-02, as corrected):
+# Based on information we have received from the Australian Antarctic
+# Division, Casey station and Macquarie Island station will move to Tasmanian
+# daylight savings time on Sunday 4 October. This will take effect from 0001
+# hrs on Sunday 4 October 2020 and will mean Casey and Macquarie Island will
+# be on the same time zone as Hobart.  Some past dates too for this 3 hour
+# time change back and forth between UTC+8 and UTC+11 for Casey:
+# - 2018 Oct  7 4:00 - 2019 Mar 17 3:00 - 2019 Oct  4 3:00 - 2020 Mar  8 3:00
+# and now - 2020 Oct  4 0:01
+
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
-Zone Antarctica/Casey	0	-	-00	1969
-			8:00	-	+08	2009 Oct 18  2:00
+Zone Antarctica/Casey	 0	-	-00	1969
+			 8:00	-	+08	2009 Oct 18  2:00
 			11:00	-	+11	2010 Mar  5  2:00
-			8:00	-	+08	2011 Oct 28  2:00
+			 8:00	-	+08	2011 Oct 28  2:00
 			11:00	-	+11	2012 Feb 21 17:00u
-			8:00	-	+08	2016 Oct 22
+			 8:00	-	+08	2016 Oct 22
 			11:00	-	+11	2018 Mar 11  4:00
-			8:00	-	+08
+			 8:00	-	+08	2018 Oct  7  4:00
+			11:00	-	+11	2019 Mar 17  3:00
+			 8:00	-	+08	2019 Oct  4  3:00
+			11:00	-	+11	2020 Mar  8  3:00
+			 8:00	-	+08	2020 Oct  4  0:01
+			11:00	-	+11
 Zone Antarctica/Davis	0	-	-00	1957 Jan 13
 			7:00	-	+07	1964 Nov
 			0	-	-00	1969 Feb
@@ -224,7 +239,7 @@
 # suggested by Bengt-Inge Larsson comment them out for now, and approximate
 # with only UTC and CEST.  Uncomment them when 2014b is more prevalent.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 #Rule	Troll	2005	max	-	Mar	 1	1:00u	1:00	+01
 Rule	Troll	2005	max	-	Mar	lastSun	1:00u	2:00	+02
 #Rule	Troll	2005	max	-	Oct	lastSun	1:00u	1:00	+01
--- contrib/tzdata/asia.orig
+++ contrib/tzdata/asia
@@ -70,7 +70,7 @@
 ###############################################################################
 
 # These rules are stolen from the 'europe' file.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	EUAsia	1981	max	-	Mar	lastSun	 1:00u	1:00	S
 Rule	EUAsia	1979	1995	-	Sep	lastSun	 1:00u	0	-
 Rule	EUAsia	1996	max	-	Oct	lastSun	 1:00u	0	-
@@ -114,7 +114,7 @@
 # or
 # (brief)
 # http://www.worldtimezone.com/dst_news/dst_news_armenia03.html
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule Armenia	2011	only	-	Mar	lastSun	 2:00s	1:00	-
 Rule Armenia	2011	only	-	Oct	lastSun	 2:00s	0	-
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
@@ -140,7 +140,7 @@
 # http://vestnikkavkaza.net/news/Azerbaijani-Cabinet-of-Ministers-cancels-daylight-saving-time.html
 # http://en.apa.az/xeber_azerbaijan_abolishes_daylight_savings_ti_240862.html
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Azer	1997	2015	-	Mar	lastSun	 4:00	1:00	-
 Rule	Azer	1997	2015	-	Oct	lastSun	 5:00	0	-
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
@@ -227,7 +227,7 @@
 # http://www.thedailystar.net/newDesign/latest_news.php?nid=22817
 # http://www.worldtimezone.com/dst_news/dst_news_bangladesh06.html
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Dhaka	2009	only	-	Jun	19	23:00	1:00	-
 Rule	Dhaka	2009	only	-	Dec	31	24:00	0	-
 
@@ -303,7 +303,7 @@
 # generally esteemed a success, it was announced early in 1920 that it would
 # not be repeated."
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Shang	1919	only	-	Apr	12	24:00	1:00	D
 Rule	Shang	1919	only	-	Sep	30	24:00	0	S
 
@@ -399,7 +399,7 @@
 # the Yangtze river delta area during that period of time although the scope
 # of such use will need to be investigated to determine.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Shang	1940	only	-	Jun	 1	 0:00	1:00	D
 Rule	Shang	1940	only	-	Oct	12	24:00	0	S
 Rule	Shang	1941	only	-	Mar	15	 0:00	1:00	D
@@ -462,7 +462,7 @@
 # to begin on 17 April.
 # http://data.people.com.cn/pic/101p/1988/04/1988041201.jpg
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	PRC	1986	only	-	May	 4	 2:00	1:00	D
 Rule	PRC	1986	1991	-	Sep	Sun>=11	 2:00	0	S
 Rule	PRC	1987	1991	-	Apr	Sun>=11	 2:00	1:00	D
@@ -846,7 +846,7 @@
 # or dates for the 1942 and 1945 transitions.
 # The Japanese occupation of Hong Kong began 1941-12-25.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	HK	1946	only	-	Apr	21	0:00	1:00	S
 Rule	HK	1946	only	-	Dec	1	3:30s	0	-
 Rule	HK	1947	only	-	Apr	13	3:30s	1:00	S
@@ -973,7 +973,7 @@
 # until 1945-09-21 at 01:00, overriding Shanks & Pottenger.
 # Likewise, use Yu-Cheng Chuang's data for DST in Taiwan.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Taiwan	1946	only	-	May	15	0:00	1:00	D
 Rule	Taiwan	1946	only	-	Oct	1	0:00	0	S
 Rule	Taiwan	1947	only	-	Apr	15	0:00	1:00	D
@@ -1099,7 +1099,7 @@
 # The 1904 decree says that Macau changed from the meridian of
 # Fortaleza do Monte, presumably the basis for the 7:34:10 for LMT.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Macau	1942	1943	-	Apr	30	23:00	1:00	-
 Rule	Macau	1942	only	-	Nov	17	23:00	0	-
 Rule	Macau	1943	only	-	Sep	30	23:00	0	S
@@ -1157,7 +1157,7 @@
 # Cyprus to remain united in time.  Cyprus Mail 2017-10-17.
 # https://cyprus-mail.com/2017/10/17/cyprus-remain-united-time/
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Cyprus	1975	only	-	Apr	13	0:00	1:00	S
 Rule	Cyprus	1975	only	-	Oct	12	0:00	0	-
 Rule	Cyprus	1976	only	-	May	15	0:00	1:00	S
@@ -1534,7 +1534,7 @@
 # be changed back to its previous state on the 24 hours of the
 # thirtieth day of Shahrivar.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Iran	1978	1980	-	Mar	20	24:00	1:00	-
 Rule	Iran	1978	only	-	Oct	20	24:00	0	-
 Rule	Iran	1979	only	-	Sep	18	24:00	0	-
@@ -1676,7 +1676,7 @@
 # We have published a short article in English about the change:
 # https://www.timeanddate.com/news/time/iraq-dumps-daylight-saving.html
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Iraq	1982	only	-	May	1	0:00	1:00	-
 Rule	Iraq	1982	1984	-	Oct	1	0:00	0	-
 Rule	Iraq	1983	only	-	Mar	31	0:00	1:00	-
@@ -1699,6 +1699,10 @@
 
 # Israel
 
+# For more info about the motivation for DST in Israel, see:
+# Barak Y. Israel's Daylight Saving Time controversy. Israel Affairs.
+# 2020-08-11. https://doi.org/10.1080/13537121.2020.1806564
+
 # From Ephraim Silverberg (2001-01-11):
 #
 # I coined "IST/IDT" circa 1988.  Until then there were three
@@ -1720,7 +1724,7 @@
 # family is from India).
 
 # From Shanks & Pottenger:
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Zion	1940	only	-	Jun	 1	0:00	1:00	D
 Rule	Zion	1942	1944	-	Nov	 1	0:00	0	S
 Rule	Zion	1943	only	-	Apr	 1	2:00	1:00	D
@@ -1812,7 +1816,7 @@
 # (except in 2002) is three nights before Yom Kippur [Day of Atonement]
 # (the eve of the 7th of Tishrei in the lunar Hebrew calendar).
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Zion	1989	only	-	Apr	30	0:00	1:00	D
 Rule	Zion	1989	only	-	Sep	 3	0:00	0	S
 Rule	Zion	1990	only	-	Mar	25	0:00	1:00	D
@@ -1828,7 +1832,7 @@
 # Ministry of Interior, Jerusalem, Israel.  The spokeswoman can be reached by
 # calling the office directly at 972-2-6701447 or 972-2-6701448.
 
-# Rule	NAME    FROM    TO      TYPE    IN      ON      AT      SAVE    LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Zion	1994	only	-	Apr	 1	0:00	1:00	D
 Rule	Zion	1994	only	-	Aug	28	0:00	0	S
 Rule	Zion	1995	only	-	Mar	31	0:00	1:00	D
@@ -1848,7 +1852,7 @@
 #
 #       where YYYY is the relevant year.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Zion	1996	only	-	Mar	15	0:00	1:00	D
 Rule	Zion	1996	only	-	Sep	16	0:00	0	S
 Rule	Zion	1997	only	-	Mar	21	0:00	1:00	D
@@ -1871,7 +1875,7 @@
 #
 #	ftp://ftp.cs.huji.ac.il/pub/tz/announcements/2000-2004.ps.gz
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Zion	2000	only	-	Apr	14	2:00	1:00	D
 Rule	Zion	2000	only	-	Oct	 6	1:00	0	S
 Rule	Zion	2001	only	-	Apr	 9	1:00	1:00	D
@@ -1893,7 +1897,7 @@
 #
 #	ftp://ftp.cs.huji.ac.il/pub/tz/announcements/2005+beyond.ps
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Zion	2005	2012	-	Apr	Fri<=1	2:00	1:00	D
 Rule	Zion	2005	only	-	Oct	 9	2:00	0	S
 Rule	Zion	2006	only	-	Oct	 1	2:00	0	S
@@ -1913,7 +1917,7 @@
 # As of 2013, DST starts at 02:00 on the Friday before the last Sunday
 # in March.  DST ends at 02:00 on the last Sunday of October.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Zion	2013	max	-	Mar	Fri>=23	2:00	1:00	D
 Rule	Zion	2013	max	-	Oct	lastSun	2:00	0	S
 
@@ -2013,7 +2017,7 @@
 # do in any POSIX or C platform.  The "25:00" assumes zic from 2007 or later,
 # which should be safe now.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Japan	1948	only	-	May	Sat>=1	24:00	1:00	D
 Rule	Japan	1948	1951	-	Sep	Sat>=8	25:00	0	S
 Rule	Japan	1949	only	-	Apr	Sat>=1	24:00	1:00	D
@@ -2090,7 +2094,7 @@
 # From Paul Eggert (2013-12-11):
 # As Steffen suggested, consider the past 21-month experiment to be DST.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Jordan	1973	only	-	Jun	6	0:00	1:00	S
 Rule	Jordan	1973	1975	-	Oct	1	0:00	0	-
 Rule	Jordan	1974	1977	-	May	1	0:00	1:00	S
@@ -2416,7 +2420,7 @@
 # Our government cancels daylight saving time 6th of August 2005.
 # From 2005-08-12 our GMT-offset is +6, w/o any daylight saving.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Kyrgyz	1992	1996	-	Apr	Sun>=7	0:00s	1:00	-
 Rule	Kyrgyz	1992	1996	-	Sep	lastSun	0:00	0	-
 Rule	Kyrgyz	1997	2005	-	Mar	lastSun	2:30	1:00	-
@@ -2472,7 +2476,7 @@
 # follow and continued to use GMT+9:00 for interoperability.
 
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	ROK	1948	only	-	Jun	 1	 0:00	1:00	D
 Rule	ROK	1948	only	-	Sep	12	24:00	0	S
 Rule	ROK	1949	only	-	Apr	 3	 0:00	1:00	D
@@ -2560,7 +2564,7 @@
 
 
 # Lebanon
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Lebanon	1920	only	-	Mar	28	0:00	1:00	S
 Rule	Lebanon	1920	only	-	Oct	25	0:00	0	-
 Rule	Lebanon	1921	only	-	Apr	3	0:00	1:00	S
@@ -2590,7 +2594,7 @@
 			2:00	Lebanon	EE%sT
 
 # Malaysia
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	NBorneo	1935	1941	-	Sep	14	0:00	0:20	-
 Rule	NBorneo	1935	1941	-	Dec	14	0:00	0	-
 #
@@ -2735,7 +2739,7 @@
 # September daylight saving time ends.  Source:
 # http://zasag.mn/news/view/8969
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Mongol	1983	1984	-	Apr	1	0:00	1:00	-
 Rule	Mongol	1983	only	-	Oct	1	0:00	0	-
 # Shanks & Pottenger and IATA SSIM say 1990s switches occurred at 00:00,
@@ -2923,7 +2927,7 @@
 # "People laud PM's announcement to end DST"
 # http://www.app.com.pk/en_/index.php?option=com_content&task=view&id=99374&Itemid=2
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule Pakistan	2002	only	-	Apr	Sun>=2	0:00	1:00	S
 Rule Pakistan	2002	only	-	Oct	Sun>=2	0:00	0	-
 Rule Pakistan	2008	only	-	Jun	1	0:00	1:00	S
@@ -3217,15 +3221,42 @@
 
 # From Sharef Mustafa (2019-10-18):
 # Palestine summer time will end on midnight Oct 26th 2019 ...
-# http://www.palestinecabinet.gov.ps/website/ar/ViewDetails?ID=43948
 #
-# From Paul Eggert (2019-04-10):
-# For now, guess spring-ahead transitions are March's last Friday at 00:00.
+# From Steffen Thorsen (2020-10-20):
+# Some sources such as these say, and display on clocks, that DST ended at
+# midnight last year...
+# https://www.amad.ps/ar/post/320006
 #
-# From Tim Parenti (2016-10-19):
-# Predict fall transitions on October's last Saturday at 01:00 from now on.
+# From Tim Parenti (2020-10-20):
+# The report of the Palestinian Cabinet meeting of 2019-10-14 confirms
+# a decision on (translated): "The start of the winter time in Palestine, by
+# delaying the clock by sixty minutes, starting from midnight on Friday /
+# Saturday corresponding to 26/10/2019."
+# http://www.palestinecabinet.gov.ps/portal/meeting/details/43948
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# From Sharef Mustafa (2020-10-20):
+# As per the palestinian cabinet announcement yesterday , the day light saving
+# shall [end] on Oct 24th 2020 at 01:00AM by delaying the clock by 60 minutes.
+# http://www.palestinecabinet.gov.ps/portal/Meeting/Details/51584
+
+# From Tim Parenti (2020-10-20):
+# Predict future fall transitions at 01:00 on the Saturday preceding October's
+# last Sunday (i.e., Sat>=24).  This is consistent with our predictions since
+# 2016, although the time of the change differed slightly in 2019.
+
+# From Pierre Cashon (2020-10-20):
+# The summer time this year started on March 28 at 00:00.
+# https://wafa.ps/ar_page.aspx?id=GveQNZa872839351758aGveQNZ
+# http://www.palestinecabinet.gov.ps/portal/meeting/details/50284
+# The winter time in 2015 started on October 23 at 01:00.
+# https://wafa.ps/ar_page.aspx?id=CgpCdYa670694628582aCgpCdY
+# http://www.palestinecabinet.gov.ps/portal/meeting/details/27583
+#
+# From Paul Eggert (2019-04-10):
+# For now, guess spring-ahead transitions are at 00:00 on the Saturday
+# preceding March's last Sunday (i.e., Sat>=24).
+
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule EgyptAsia	1957	only	-	May	10	0:00	1:00	S
 Rule EgyptAsia	1957	1958	-	Oct	 1	0:00	0	-
 Rule EgyptAsia	1958	only	-	May	 1	0:00	1:00	S
@@ -3239,10 +3270,10 @@
 Rule Palestine	2005	only	-	Oct	 4	2:00	0	-
 Rule Palestine	2006	2007	-	Apr	 1	0:00	1:00	S
 Rule Palestine	2006	only	-	Sep	22	0:00	0	-
-Rule Palestine	2007	only	-	Sep	Thu>=8	2:00	0	-
+Rule Palestine	2007	only	-	Sep	13	2:00	0	-
 Rule Palestine	2008	2009	-	Mar	lastFri	0:00	1:00	S
 Rule Palestine	2008	only	-	Sep	 1	0:00	0	-
-Rule Palestine	2009	only	-	Sep	Fri>=1	1:00	0	-
+Rule Palestine	2009	only	-	Sep	 4	1:00	0	-
 Rule Palestine	2010	only	-	Mar	26	0:00	1:00	S
 Rule Palestine	2010	only	-	Aug	11	0:00	0	-
 Rule Palestine	2011	only	-	Apr	 1	0:01	1:00	S
@@ -3251,12 +3282,16 @@
 Rule Palestine	2011	only	-	Sep	30	0:00	0	-
 Rule Palestine	2012	2014	-	Mar	lastThu	24:00	1:00	S
 Rule Palestine	2012	only	-	Sep	21	1:00	0	-
-Rule Palestine	2013	only	-	Sep	Fri>=21	0:00	0	-
-Rule Palestine	2014	2015	-	Oct	Fri>=21	0:00	0	-
-Rule Palestine	2015	only	-	Mar	lastFri	24:00	1:00	S
+Rule Palestine	2013	only	-	Sep	27	0:00	0	-
+Rule Palestine	2014	only	-	Oct	24	0:00	0	-
+Rule Palestine	2015	only	-	Mar	28	0:00	1:00	S
+Rule Palestine	2015	only	-	Oct	23	1:00	0	-
 Rule Palestine	2016	2018	-	Mar	Sat>=24	1:00	1:00	S
-Rule Palestine	2016	max	-	Oct	lastSat	1:00	0	-
-Rule Palestine	2019	max	-	Mar	lastFri	0:00	1:00	S
+Rule Palestine	2016	2018	-	Oct	Sat>=24	1:00	0	-
+Rule Palestine	2019	only	-	Mar	29	0:00	1:00	S
+Rule Palestine	2019	only	-	Oct	Sat>=24	0:00	0	-
+Rule Palestine	2020	max	-	Mar	Sat>=24	0:00	1:00	S
+Rule Palestine	2020	max	-	Oct	Sat>=24	1:00	0	-
 
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Gaza	2:17:52	-	LMT	1900 Oct
@@ -3325,7 +3360,7 @@
 # influence of the sources.  There is no current abbreviation for DST,
 # so use "PDT", the usual American style.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Phil	1936	only	-	Nov	1	0:00	1:00	D
 Rule	Phil	1937	only	-	Feb	1	0:00	0	S
 Rule	Phil	1954	only	-	Apr	12	0:00	1:00	D
@@ -3473,7 +3508,7 @@
 			5:30	-	+0530
 
 # Syria
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Syria	1920	1923	-	Apr	Sun>=15	2:00	1:00	S
 Rule	Syria	1920	1923	-	Oct	Sun>=1	2:00	0	-
 Rule	Syria	1962	only	-	Apr	29	2:00	1:00	S
--- contrib/tzdata/australasia.orig
+++ contrib/tzdata/australasia
@@ -13,7 +13,7 @@
 
 # Please see the notes below for the controversy about "EST" versus "AEST" etc.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Aus	1917	only	-	Jan	 1	0:01	1:00	D
 Rule	Aus	1917	only	-	Mar	25	2:00	0	S
 Rule	Aus	1942	only	-	Jan	 1	2:00	1:00	D
@@ -32,7 +32,7 @@
 			 9:30	Aus	AC%sT
 # Western Australia
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	AW	1974	only	-	Oct	lastSun	2:00s	1:00	D
 Rule	AW	1975	only	-	Mar	Sun>=1	2:00s	0	S
 Rule	AW	1983	only	-	Oct	lastSun	2:00s	1:00	D
@@ -70,7 +70,7 @@
 # applies to all of the Whitsundays.
 # http://www.australia.gov.au/about-australia/australian-story/austn-islands
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	AQ	1971	only	-	Oct	lastSun	2:00s	1:00	D
 Rule	AQ	1972	only	-	Feb	lastSun	2:00s	0	S
 Rule	AQ	1989	1991	-	Oct	lastSun	2:00s	1:00	D
@@ -86,7 +86,7 @@
 			10:00	Holiday	AE%sT
 
 # South Australia
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	AS	1971	1985	-	Oct	lastSun	2:00s	1:00	D
 Rule	AS	1986	only	-	Oct	19	2:00s	1:00	D
 Rule	AS	1987	2007	-	Oct	lastSun	2:00s	1:00	D
@@ -114,7 +114,7 @@
 # http://www.bom.gov.au/climate/averages/tables/dst_times.shtml
 # says King Island didn't observe DST from WWII until late 1971.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	AT	1967	only	-	Oct	Sun>=1	2:00s	1:00	D
 Rule	AT	1968	only	-	Mar	lastSun	2:00s	0	S
 Rule	AT	1968	1985	-	Oct	lastSun	2:00s	1:00	D
@@ -147,7 +147,7 @@
 			10:00	AT	AE%sT
 
 # Victoria
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	AV	1971	1985	-	Oct	lastSun	2:00s	1:00	D
 Rule	AV	1972	only	-	Feb	lastSun	2:00s	0	S
 Rule	AV	1973	1985	-	Mar	Sun>=1	2:00s	0	S
@@ -168,7 +168,7 @@
 			10:00	AV	AE%sT
 
 # New South Wales
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	AN	1971	1985	-	Oct	lastSun	2:00s	1:00	D
 Rule	AN	1972	only	-	Feb	27	2:00s	0	S
 Rule	AN	1973	1981	-	Mar	Sun>=1	2:00s	0	S
@@ -197,7 +197,7 @@
 			9:30	AS	AC%sT
 
 # Lord Howe Island
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	LH	1981	1984	-	Oct	lastSun	2:00	1:00	-
 Rule	LH	1982	1985	-	Mar	Sun>=1	2:00	0	-
 Rule	LH	1985	only	-	Oct	lastSun	2:00	0:30	-
@@ -252,8 +252,9 @@
 			10:00	Aus	AE%sT	1919 Apr  1  0:00s
 			0	-	-00	1948 Mar 25
 			10:00	Aus	AE%sT	1967
-			10:00	AT	AE%sT	2010 Apr  4  3:00
-			11:00	-	+11
+			10:00	AT	AE%sT	2010
+			10:00	1:00	AEDT	2011
+			10:00	AT	AE%sT
 
 # Christmas
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
@@ -380,7 +381,20 @@
 # From Michael Deckers (2019-08-06):
 # https://www.laws.gov.fj/LawsAsMade/downloadfile/848
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# From Raymond Kumar (2020-10-08):
+# [DST in Fiji] is from December 20th 2020, till 17th January 2021.
+# From Alan Mintz (2020-10-08):
+# https://www.laws.gov.fj/LawsAsMade/GetFile/1071
+# From Tim Parenti (2020-10-08):
+# https://www.fijivillage.com/news/Daylight-saving-from-Dec-20th-this-year-to-Jan-17th-2021-8rf4x5/
+# "Minister for Employment, Parveen Bala says they had never thought of
+# stopping daylight saving. He says it was just to decide on when it should
+# start and end.  Bala says it is a short period..."
+# Since the end date is still in line with our ongoing predictions, assume for
+# now that the later-than-usual start date is a one-time departure from the
+# recent second Sunday in November pattern.
+
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Fiji	1998	1999	-	Nov	Sun>=1	2:00	1:00	-
 Rule	Fiji	1999	2000	-	Feb	lastSun	3:00	0	-
 Rule	Fiji	2009	only	-	Nov	29	2:00	1:00	-
@@ -391,7 +405,9 @@
 Rule	Fiji	2014	only	-	Jan	Sun>=18	2:00	0	-
 Rule	Fiji	2014	2018	-	Nov	Sun>=1	2:00	1:00	-
 Rule	Fiji	2015	max	-	Jan	Sun>=12	3:00	0	-
-Rule	Fiji	2019	max	-	Nov	Sun>=8	2:00	1:00	-
+Rule	Fiji	2019	only	-	Nov	Sun>=8	2:00	1:00	-
+Rule	Fiji	2020	only	-	Dec	20	2:00	1:00	-
+Rule	Fiji	2021	max	-	Nov	Sun>=8	2:00	1:00	-
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Pacific/Fiji	11:55:44 -	LMT	1915 Oct 26 # Suva
 			12:00	Fiji	+12/+13
@@ -409,7 +425,7 @@
 
 # Guam
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 # http://guamlegislature.com/Public_Laws_5th/PL05-025.pdf
 # http://documents.guam.gov/wp-content/uploads/E.O.-59-7-Guam-Daylight-Savings-Time-May-6-1959.pdf
 Rule	Guam	1959	only	-	Jun	27	2:00	1:00	D
@@ -520,7 +536,7 @@
 			12:00	-	+12
 
 # New Caledonia
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	NC	1977	1978	-	Dec	Sun>=1	0:00	1:00	-
 Rule	NC	1978	1979	-	Feb	27	0:00	0	-
 Rule	NC	1996	only	-	Dec	 1	2:00s	1:00	-
@@ -535,7 +551,7 @@
 
 # New Zealand
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	NZ	1927	only	-	Nov	 6	2:00	1:00	S
 Rule	NZ	1928	only	-	Mar	 4	2:00	0	M
 Rule	NZ	1928	1933	-	Oct	Sun>=8	2:00	0:30	S
@@ -587,7 +603,7 @@
 
 # Cook Is
 # From Shanks & Pottenger:
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Cook	1978	only	-	Nov	12	0:00	0:30	-
 Rule	Cook	1979	1991	-	Mar	Sun>=1	0:00	0	-
 Rule	Cook	1979	1990	-	Oct	lastSun	0:00	0:30	-
@@ -732,7 +748,7 @@
 # That web page currently lists transitions for 2012/3 and 2013/4.
 # Assume the pattern instituted in 2012 will continue indefinitely.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	WS	2010	only	-	Sep	lastSun	0:00	1	-
 Rule	WS	2011	only	-	Apr	Sat>=1	4:00	0	-
 Rule	WS	2011	only	-	Sep	lastSat	3:00	1	-
@@ -776,7 +792,7 @@
 			13:00	-	+13
 
 # Tonga
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Tonga	1999	only	-	Oct	 7	2:00s	1:00	-
 Rule	Tonga	2000	only	-	Mar	19	2:00s	0	-
 Rule	Tonga	2000	2001	-	Nov	Sun>=1	2:00	1:00	-
@@ -857,7 +873,7 @@
 
 
 # Vanuatu
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Vanuatu	1983	only	-	Sep	25	0:00	1:00	-
 Rule	Vanuatu	1984	1991	-	Mar	Sun>=23	0:00	0	-
 Rule	Vanuatu	1984	only	-	Oct	23	0:00	1:00	-
--- contrib/tzdata/backzone.orig
+++ contrib/tzdata/backzone
@@ -150,7 +150,7 @@
 # Whitman gives Mar 31 - Aug 31 for 1931 on.
 # The International Hydrographic Bulletin, 1932-33, p 63 says that
 # Sierra Leone would advance its clocks by 20 minutes on 1933-10-01.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	SL	1935	1942	-	Jun	 1	0:00	0:40	-0020
 Rule	SL	1935	1942	-	Oct	 1	0:00	0	-01
 Rule	SL	1957	1962	-	Jun	 1	0:00	1:00	+01
@@ -351,7 +351,7 @@
 # Pottenger data.  The post-1970 entries have been corrected, but the
 # pre-1970 entries are unchecked and probably have errors.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Mont	1917	only	-	Mar	25	2:00	1:00	D
 Rule	Mont	1917	only	-	Apr	24	0:00	0	S
 Rule	Mont	1919	only	-	Mar	31	2:30	1:00	D
@@ -459,7 +459,34 @@
 			3:00	-	+03
 
 # Bahrain
-Zone	Asia/Bahrain	3:22:20 -	LMT	1920     # Manamah
+#
+# From Paul Eggert (2020-07-23):
+# Most of this data comes from:
+# Stewart A. Why Gulf Standard Time is far from standard: the fascinating story
+# behind the time zone's invention. The National (Abu Dhabi). 2020-07-22.
+# https://www.thenational.ae/arts-culture/why-gulf-standard-time-is-far-from-standard-the-fascinating-story-behind-the-time-zone-s-invention-1.1052589
+# Stewart writes that before 1941 some companies in Bahrain were at +0330 and
+# others at +0323.  Reginald George Alban, a British political agent based in
+# Manama, worked to standardize this, and from 1941-07-20 Bahrain was at
+# +0330.  However, BOAC asked that clocks be moved to gain more light at day's
+# end, so Bahrain switched to +04 on 1944-01-01.
+#
+# Re the 1941 transition, Stewart privately sent me this citation:
+# "File 16/53 Enquiries Re: Calculation of Local Time", British Library: India
+# Office Records and Private Papers, IOR/R/15/2/1564, in Qatar Digital Library
+# https://www.qdl.qa/archive/81055/vdc_100000000282.0x00012b
+# It says there was no real standard in Bahrain before 1941-07-20.
+# +0330 was used by steamers of the British India Co, by Petroleum Concessions
+# and by Cable & Wireless; +0323 was used by the Eastern Bank Ltd, BOAC, and
+# Bahrein Petroleum (Bapco), and California Arabian Standard Oil Co (Casoc)
+# adopted DST effective 1941-05-24.  Alban suggested adopting DST, R.B. Coomb
+# of C&W countersuggested +0330, and although C.A. Rodstrom of Casoc (formerly
+# of Bapco) stated that Bahrain had formerly used +0330 before Bapco arrived
+# but Bapco switched to +0323 because of "constant confusion", the consensus
+# was +0330.  The government adopted +0330 in 1941-07-20 and companies seem to
+# have switched by 08-01.  No time of day was given for the 1940s transitions.
+Zone	Asia/Bahrain	3:22:20 -	LMT	1941 Jul 20  # Manamah
+			3:30	-	+0330	1944 Jan  1
 			4:00	-	+04	1972 Jun
 			3:00	-	+03
 
--- contrib/tzdata/europe.orig
+++ contrib/tzdata/europe
@@ -388,7 +388,7 @@
 # http://www.irishstatutebook.ie/eli/1926/sro/919/made/en/print
 # http://www.irishstatutebook.ie/eli/1947/sro/71/made/en/print
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 # Summer Time Act, 1916
 Rule	GB-Eire	1916	only	-	May	21	2:00s	1:00	BST
 Rule	GB-Eire	1916	only	-	Oct	 1	2:00s	0	GMT
@@ -529,7 +529,7 @@
 # The following is like GB-Eire and EU, except with standard time in
 # summer and negative daylight saving time in winter.  It is for when
 # negative SAVE values are used.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Eire	1971	only	-	Oct	31	 2:00u	-1:00	-
 Rule	Eire	1972	1980	-	Mar	Sun>=16	 2:00u	0	-
 Rule	Eire	1972	1980	-	Oct	Sun>=23	 2:00u	-1:00	-
@@ -566,7 +566,7 @@
 # predecessor organization, the European Communities.
 # For brevity they are called "EU rules" elsewhere in this file.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	EU	1977	1980	-	Apr	Sun>=1	 1:00u	1:00	S
 Rule	EU	1977	only	-	Sep	lastSun	 1:00u	0	-
 Rule	EU	1978	only	-	Oct	 1	 1:00u	0	-
@@ -606,13 +606,13 @@
 # corrected in version 2008d). The circumstantial evidence is simply the
 # tz database itself, as seen below:
 #
-# Zone Europe/Paris 0:09:21 - LMT 1891 Mar 15  0:01
+# Zone Europe/Paris ...
 #    0:00 France WE%sT 1945 Sep 16  3:00
 #
-# Zone Europe/Monaco 0:29:32 - LMT 1891 Mar 15
+# Zone Europe/Monaco ...
 #    0:00 France WE%sT 1945 Sep 16  3:00
 #
-# Zone Europe/Belgrade 1:22:00 - LMT 1884
+# Zone Europe/Belgrade ...
 #    1:00 1:00 CEST 1945 Sep 16  2:00s
 #
 # Rule France 1945 only - Sep 16  3:00 0 -
@@ -658,7 +658,7 @@
 #
 # The 1917-1921 decree URLs are from Alexander Belopolsky (2016-08-23).
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Russia	1917	only	-	Jul	 1	23:00	1:00	MST  # Moscow Summer Time
 #
 # Decree No. 142 (1917-12-22) http://istmat.info/node/28137
@@ -772,7 +772,7 @@
 
 
 # Albania
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Albania	1940	only	-	Jun	16	0:00	1:00	S
 Rule	Albania	1942	only	-	Nov	 2	3:00	0	-
 Rule	Albania	1943	only	-	Mar	29	2:00	1:00	S
@@ -826,7 +826,7 @@
 # In 1946 the end of DST was on Monday, 7 October 1946, at 3:00 am.
 # Shanks had this right.  Source: Die Weltpresse, 5. Oktober 1946, page 5.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Austria	1920	only	-	Apr	 5	2:00s	1:00	S
 Rule	Austria	1920	only	-	Sep	13	2:00s	0	-
 Rule	Austria	1946	only	-	Apr	14	2:00s	1:00	S
@@ -913,7 +913,7 @@
 # The 1918 rules are listed for completeness; they apply to unoccupied Belgium.
 # Assume Brussels switched to WET in 1918 when the armistice took effect.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Belgium	1918	only	-	Mar	 9	 0:00s	1:00	S
 Rule	Belgium	1918	1919	-	Oct	Sat>=1	23:00s	0	-
 Rule	Belgium	1919	only	-	Mar	 1	23:00s	1:00	S
@@ -973,7 +973,7 @@
 # EET -> EETDST is in 03:00 Local time in last Sunday of March ...
 # EETDST -> EET is in 04:00 Local time in last Sunday of October
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Bulg	1979	only	-	Mar	31	23:00	1:00	S
 Rule	Bulg	1979	only	-	Oct	 1	 1:00	0	-
 Rule	Bulg	1980	1982	-	Apr	Sat>=1	23:00	1:00	S
@@ -1005,7 +1005,7 @@
 # We know of no English-language name for historical Czech winter time;
 # abbreviate it as "GMT", as it happened to be GMT.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Czech	1945	only	-	Apr	Mon>=1	2:00s	1:00	S
 Rule	Czech	1945	only	-	Oct	 1	2:00s	0	-
 Rule	Czech	1946	only	-	May	 6	2:00s	1:00	S
@@ -1029,17 +1029,16 @@
 # Denmark, Faroe Islands, and Greenland
 
 # From Jesper Nørgaard Welen (2005-04-26):
-# http://www.hum.aau.dk/~poe/tid/tine/DanskTid.htm says that the law
-# [introducing standard time] was in effect from 1894-01-01....
-# The page http://www.retsinfo.dk/_GETDOCI_/ACCN/A18930008330-REGL
+# the law [introducing standard time] was in effect from 1894-01-01....
+# The page https://www.retsinformation.dk/eli/lta/1893/83
 # confirms this, and states that the law was put forth 1893-03-29.
 #
 # The EU [actually, EEC and Euratom] treaty with effect from 1973:
-# http://www.retsinfo.dk/_GETDOCI_/ACCN/A19722110030-REGL
+# https://www.retsinformation.dk/eli/lta/1972/21100
 #
 # This provoked a new law from 1974 to make possible summer time changes
 # in subsequent decrees with the law
-# http://www.retsinfo.dk/_GETDOCI_/ACCN/A19740022330-REGL
+# https://www.retsinformation.dk/eli/lta/1974/223
 #
 # It seems however that no decree was set forward until 1980.  I have
 # not found any decree, but in another related law, the effecting DST
@@ -1051,7 +1050,7 @@
 # The law is about the management of the extra hour, concerning
 # working hours reported and effect on obligatory-rest rules (which
 # was suspended on that night):
-# http://www.retsinfo.dk/_GETDOCI_/ACCN/C19801120554-REGL
+# https://web.archive.org/web/20140104053304/https://www.retsinformation.dk/Forms/R0710.aspx?id=60267
 
 # From Jesper Nørgaard Welen (2005-06-11):
 # The Herning Folkeblad (1980-09-26) reported that the night between
@@ -1061,7 +1060,7 @@
 # Hence the "02:00" of the 1980 law refers to standard time, not
 # wall-clock time, and so the EU rules were in effect in 1980.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Denmark	1916	only	-	May	14	23:00	1:00	S
 Rule	Denmark	1916	only	-	Sep	30	23:00	0	-
 Rule	Denmark	1940	only	-	May	15	 0:00	1:00	S
@@ -1163,7 +1162,7 @@
 # http://naalakkersuisut.gl/~/media/Nanoq/Files/Attached%20Files/Engelske-tekster/Legislation/Executive%20Order%20National%20Park.rtf
 # It is their only National Park.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Thule	1991	1992	-	Mar	lastSun	2:00	1:00	D
 Rule	Thule	1991	1992	-	Sep	lastSun	2:00	0	S
 Rule	Thule	1993	2006	-	Apr	Sun>=1	2:00	1:00	D
@@ -1294,7 +1293,7 @@
 # From Paul Eggert (2014-06-14):
 # Go with Oja over Shanks.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Finland	1942	only	-	Apr	2	24:00	1:00	S
 Rule	Finland	1942	only	-	Oct	4	1:00	0	-
 Rule	Finland	1981	1982	-	Mar	lastSun	2:00	1:00	S
@@ -1326,10 +1325,58 @@
 # Françoise Gauquelin, Problèmes de l'heure résolus en astrologie,
 # Guy Trédaniel, Paris 1987
 
+# From Michael Deckers (2020-06-11):
+# the law of 1891 <https://gallica.bnf.fr/ark:/12148/bpt6k64415343.texteImage>
+# was published on 1891-03-15, so it could only take force on 1891-03-16.
 
+# From Michael Deckers (2020-06-10):
+# Le Gaulois, 1911-03-11, page 1/6, online at
+# https://www.retronews.fr/societe/echo-de-presse/2018/01/29/1911-change-lheure-de-paris
+# ... [ Instantly, all pressure driven clock dials halted...  Nine minutes and
+#       twenty-one seconds later the hands resumed their circular motion. ]
+# There are also precise reports about how the change was prepared in train
+# stations: all the publicly visible clocks stopped at midnight railway time
+# (or were covered), only the chief of service had a watch, labeled
+# "Heure ancienne", that he kept running until it reached 00:04:21, when
+# he announced "Heure nouvelle".  See the "Le Petit Journal 1911-03-11".
+# https://gallica.bnf.fr/ark:/12148/bpt6k6192911/f1.item.zoom
 #
+# From Michael Deckers (2020-06-12):
+# That "all French clocks stopped" for 00:09:21 is a misreading of French
+# newspapers; this sort of adjustment applies only to certain
+# remote-controlled clocks ("pendules pneumatiques", of which there existed
+# perhaps a dozen in Paris, and which simply could not be set back remotely),
+# but not to all the clocks in all French towns and villages.  For instance,
+# the following story in the "Courrier de Saône-et-Loire" 1911-03-11, page 2:
+# only works if legal time was stepped back (was not monotone): ...
+#   [One can observe that children who had been born at midnight less 5
+#    minutes and who had died at midnight of the old time, would turn out to
+#    be dead before being born, time having been set back and having
+#    suppressed 9 minutes and 25 seconds of their existence, that is, more
+#    than they could spend.]
+#
+# From Paul Eggert (2020-06-12):
+# French time in railway stations was legally five minutes behind civil time,
+# which explains why railway "old time" ran to 00:04:21 instead of to 00:09:21.
+# The law's text (which Michael Deckers noted is at
+# <https://gallica.bnf.fr/ark:/12148/bpt6k2022333z/f2>) says only that
+# at 1911-03-11 00:00 legal time was that of Paris mean time delayed by
+# nine minutes and twenty-one seconds, and does not say how the
+# transition from Paris mean time was to occur.
+#
+# tzdb has no way to represent stopped clocks.  As the railway practice
+# was to keep a watch running on "old time" to decide when to restart
+# the other clocks, this could be modeled as a transition for "old time" at
+# 00:09:21.  However, since the law was ambiguous and clocks outside railway
+# stations were probably done haphazardly with the popular impression being
+# that the transition was done at 00:00 "old time", simply leave the time
+# blank; this causes zic to default to 00:00 "old time" which is good enough.
+# Do something similar for the 1891-03-16 transition.  There are similar
+# problems in Algiers, Monaco and Tunis.
+
+#
 # Shank & Pottenger seem to use '24:00' ambiguously; resolve it with Whitman.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	France	1916	only	-	Jun	14	23:00s	1:00	S
 Rule	France	1916	1919	-	Oct	Sun>=1	23:00s	0	-
 Rule	France	1917	only	-	Mar	24	23:00s	1:00	S
@@ -1389,13 +1436,11 @@
 # go with Excoffier's 28/3/76 0hUT and 25/9/76 23hUT.
 Rule	France	1976	only	-	Mar	28	 1:00	1:00	S
 Rule	France	1976	only	-	Sep	26	 1:00	0	-
-# Shanks & Pottenger give 0:09:20 for Paris Mean Time, and Whitman 0:09:05,
-# but Howse quotes the actual French legislation as saying 0:09:21.
-# Go with Howse.  Howse writes that the time in France was officially based
+# Howse writes that the time in France was officially based
 # on PMT-0:09:21 until 1978-08-09, when the time base finally switched to UTC.
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
-Zone	Europe/Paris	0:09:21 -	LMT	1891 Mar 15  0:01
-			0:09:21	-	PMT	1911 Mar 11  0:01 # Paris MT
+Zone	Europe/Paris	0:09:21 -	LMT	1891 Mar 16
+			0:09:21	-	PMT	1911 Mar 11 # Paris Mean Time
 # Shanks & Pottenger give 1940 Jun 14 0:00; go with Excoffier and Le Corre.
 			0:00	France	WE%sT	1940 Jun 14 23:00
 # Le Corre says Paris stuck with occupied-France time after the liberation;
@@ -1424,7 +1469,7 @@
 # this was equivalent to UT +03, not +04.
 
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Germany	1946	only	-	Apr	14	2:00s	1:00	S
 Rule	Germany	1946	only	-	Oct	 7	2:00s	0	-
 Rule	Germany	1947	1949	-	Oct	Sun>=1	2:00s	0	-
@@ -1476,7 +1521,7 @@
 			1:00	EU	CE%sT
 
 # Greece
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 # Whitman gives 1932 Jul 5 - Nov 1; go with Shanks & Pottenger.
 Rule	Greece	1932	only	-	Jul	 7	0:00	1:00	S
 Rule	Greece	1932	only	-	Sep	 1	0:00	0	-
@@ -1511,38 +1556,73 @@
 			2:00	EU	EE%sT
 
 # Hungary
-# From Paul Eggert (2014-07-15):
-# Dates for 1916-1945 are taken from:
-# Oross A. Jelen a múlt jövője: a nyári időszámítás Magyarországon 1916-1945.
-# National Archives of Hungary (2012-10-29).
-# http://mnl.gov.hu/a_het_dokumentuma/a_nyari_idoszamitas_magyarorszagon_19161945.html
-# This source does not always give times, which are taken from Shanks
-# & Pottenger (which disagree about the dates).
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Hungary	1918	only	-	Apr	 1	 3:00	1:00	S
-Rule	Hungary	1918	only	-	Sep	16	 3:00	0	-
-Rule	Hungary	1919	only	-	Apr	15	 3:00	1:00	S
-Rule	Hungary	1919	only	-	Nov	24	 3:00	0	-
+
+# From Michael Deckers (2020-06-09):
+# an Austrian encyclopedia of railroads of 1913, online at
+# http://www.zeno.org/Roell-1912/A/Eisenbahnzeit
+# says that the switch [to CET] happened on 1890-11-01.
+
+# From Géza Nyáry (2020-06-07):
+# Data for 1918-1983 are based on the archive database of Library Hungaricana.
+# The dates are collected from original, scanned governmental orders,
+# bulletins, instructions and public press.
+# [See URLs below.]
+
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
+# https://library.hungaricana.hu/hu/view/OGYK_RT_1918/?pg=238
+# https://library.hungaricana.hu/hu/view/OGYK_RT_1919/?pg=808
+# https://library.hungaricana.hu/hu/view/OGYK_RT_1920/?pg=201
+Rule	Hungary	1918	1919	-	Apr	15	 2:00	1:00	S
+Rule	Hungary	1918	1920	-	Sep	Mon>=15	 3:00	0	-
+Rule	Hungary	1920	only	-	Apr	 5	 2:00	1:00	S
+# https://library.hungaricana.hu/hu/view/OGYK_RT_1945/?pg=882
 Rule	Hungary	1945	only	-	May	 1	23:00	1:00	S
-Rule	Hungary	1945	only	-	Nov	 1	 0:00	0	-
+Rule	Hungary	1945	only	-	Nov	 1	 1:00	0	-
+# https://library.hungaricana.hu/hu/view/Delmagyarorszag_1946_03/?pg=49
 Rule	Hungary	1946	only	-	Mar	31	 2:00s	1:00	S
-Rule	Hungary	1946	1949	-	Oct	Sun>=1	 2:00s	0	-
+# https://library.hungaricana.hu/hu/view/Delmagyarorszag_1946_09/?pg=54
+Rule	Hungary	1946	only	-	Oct	 7	 2:00	0	-
+# https://library.hungaricana.hu/hu/view/KulfBelfHirek_1947_04_1__001-123/?pg=90
+# https://library.hungaricana.hu/hu/view/DunantuliNaplo_1947_09/?pg=128
+# https://library.hungaricana.hu/hu/view/KulfBelfHirek_1948_03_3__001-123/?pg=304
+# https://library.hungaricana.hu/hu/view/Zala_1948_09/?pg=64
+# https://library.hungaricana.hu/hu/view/SatoraljaujhelyiLeveltar_ZempleniNepujsag_1948/?pg=53
+# https://library.hungaricana.hu/hu/view/SatoraljaujhelyiLeveltar_ZempleniNepujsag_1948/?pg=160
+# https://library.hungaricana.hu/hu/view/UjSzo_1949_01-04/?pg=102
+# https://library.hungaricana.hu/hu/view/KeletMagyarorszag_1949_03/?pg=96
+# https://library.hungaricana.hu/hu/view/Delmagyarorszag_1949_09/?pg=94
 Rule	Hungary	1947	1949	-	Apr	Sun>=4	 2:00s	1:00	S
-Rule	Hungary	1950	only	-	Apr	17	 2:00s	1:00	S
-Rule	Hungary	1950	only	-	Oct	23	 2:00s	0	-
-Rule	Hungary	1954	1955	-	May	23	 0:00	1:00	S
-Rule	Hungary	1954	1955	-	Oct	 3	 0:00	0	-
-Rule	Hungary	1956	only	-	Jun	Sun>=1	 0:00	1:00	S
-Rule	Hungary	1956	only	-	Sep	lastSun	 0:00	0	-
-Rule	Hungary	1957	only	-	Jun	Sun>=1	 1:00	1:00	S
-Rule	Hungary	1957	only	-	Sep	lastSun	 3:00	0	-
-Rule	Hungary	1980	only	-	Apr	 6	 1:00	1:00	S
+Rule	Hungary	1947	1949	-	Oct	Sun>=1	 2:00s	0	-
+# https://library.hungaricana.hu/hu/view/DTT_KOZL_TanacsokKozlonye_1954/?pg=513
+Rule	Hungary	1954	only	-	May	23	 0:00	1:00	S
+Rule	Hungary	1954	only	-	Oct	 3	 0:00	0	-
+# https://library.hungaricana.hu/hu/view/DTT_KOZL_TanacsokKozlonye_1955/?pg=398
+Rule	Hungary	1955	only	-	May	22	 2:00	1:00	S
+Rule	Hungary	1955	only	-	Oct	 2	 3:00	0	-
+# https://library.hungaricana.hu/hu/view/HevesMegyeiNepujsag_1956_06/?pg=0
+# https://library.hungaricana.hu/hu/view/EszakMagyarorszag_1956_06/?pg=6
+# https://library.hungaricana.hu/hu/view/SzolnokMegyeiNeplap_1957_04/?pg=120
+# https://library.hungaricana.hu/hu/view/PestMegyeiHirlap_1957_09/?pg=143
+Rule	Hungary	1956	1957	-	Jun	Sun>=1	 2:00	1:00	S
+Rule	Hungary	1956	1957	-	Sep	lastSun	 3:00	0	-
+# https://library.hungaricana.hu/hu/view/DTT_KOZL_TanacsokKozlonye_1980/?pg=189
+Rule	Hungary	1980	only	-	Apr	 6	 0:00	1:00	S
+Rule	Hungary	1980	only	-	Sep	28	 1:00	0	-
+# https://library.hungaricana.hu/hu/view/DTT_KOZL_TanacsokKozlonye_1980/?pg=1227
+# https://library.hungaricana.hu/hu/view/Delmagyarorszag_1981_01/?pg=79
+# https://library.hungaricana.hu/hu/view/DTT_KOZL_TanacsokKozlonye_1982/?pg=115
+# https://library.hungaricana.hu/hu/view/DTT_KOZL_TanacsokKozlonye_1983/?pg=85
+Rule	Hungary	1981	1983	-	Mar	lastSun	 0:00	1:00	S
+Rule	Hungary	1981	1983	-	Sep	lastSun	 1:00	0	-
+#
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
-Zone	Europe/Budapest	1:16:20 -	LMT	1890 Oct
+Zone	Europe/Budapest	1:16:20 -	LMT	1890 Nov  1
 			1:00	C-Eur	CE%sT	1918
-			1:00	Hungary	CE%sT	1941 Apr  8
+# https://library.hungaricana.hu/hu/view/OGYK_RT_1941/?pg=1204
+# https://library.hungaricana.hu/hu/view/OGYK_RT_1942/?pg=3955
+			1:00	Hungary	CE%sT	1941 Apr  7 23:00
 			1:00	C-Eur	CE%sT	1945
-			1:00	Hungary	CE%sT	1980 Sep 28  2:00s
+			1:00	Hungary	CE%sT	1984
 			1:00	EU	CE%sT
 
 # Iceland
@@ -1578,7 +1658,7 @@
 # The information below is taken from the 1988 Almanak; see
 # http://www.almanak.hi.is/klukkan.html
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Iceland	1917	1919	-	Feb	19	23:00	1:00	-
 Rule	Iceland	1917	only	-	Oct	21	 1:00	0	-
 Rule	Iceland	1918	1919	-	Nov	16	 1:00	0	-
@@ -1670,7 +1750,7 @@
 # to 1944-06-04; although Rome was an open city during this period, it
 # was effectively controlled by Germany.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Italy	1916	only	-	Jun	 3	24:00	1:00	S
 Rule	Italy	1916	1917	-	Sep	30	24:00	0	-
 Rule	Italy	1917	only	-	Mar	31	24:00	1:00	S
@@ -1780,7 +1860,7 @@
 # urged Lithuania and Estonia to adopt a similar time policy, but it
 # appears that they will not do so....
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Latvia	1989	1996	-	Mar	lastSun	 2:00s	1:00	S
 Rule	Latvia	1989	1996	-	Sep	lastSun	 2:00s	0	-
 
@@ -1873,7 +1953,7 @@
 # Luxembourg
 # Whitman disagrees with most of these dates in minor ways;
 # go with Shanks & Pottenger.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Lux	1916	only	-	May	14	23:00	1:00	S
 Rule	Lux	1916	only	-	Oct	 1	 1:00	0	-
 Rule	Lux	1917	only	-	Apr	28	23:00	1:00	S
@@ -1914,7 +1994,7 @@
 # From Paul Eggert (2016-10-21):
 # Assume 1900-1972 was like Rome, overriding Shanks.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Malta	1973	only	-	Mar	31	0:00s	1:00	S
 Rule	Malta	1973	only	-	Sep	29	0:00s	0	-
 Rule	Malta	1974	only	-	Apr	21	0:00s	1:00	S
@@ -1987,7 +2067,7 @@
 # says the 2014-03-30 spring-forward transition was at 02:00 local time.
 # Guess that since 1997 Moldova has switched one hour before the EU.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Moldova	1997	max	-	Mar	lastSun	 2:00	1:00	S
 Rule	Moldova	1997	max	-	Oct	lastSun	 3:00	0	-
 
@@ -2005,11 +2085,24 @@
 			2:00	Moldova	EE%sT
 
 # Monaco
-# Shanks & Pottenger give 0:09:20 for Paris Mean Time; go with Howse's
-# more precise 0:09:21.
+#
+# From Michael Deckers (2020-06-12):
+# In the "Journal de Monaco" of 1892-05-24, online at
+# https://journaldemonaco.gouv.mc/var/jdm/storage/original/application/b1c67c12c5af11b41ea888fb048e4fe8.pdf
+# we read: ...
+#  [In virtue of a Sovereign Ordinance of the May 13 of the current [year],
+#   legal time in the Principality will be set to, from the date of June 1,
+#   1892 onwards, to the meridian of Paris, as in France.]
+# In the "Journal de Monaco" of 1911-03-28, online at
+# https://journaldemonaco.gouv.mc/var/jdm/storage/original/application/de74ffb7db53d4f599059fe8f0ed482a.pdf
+# we read an ordinance of 1911-03-16: ...
+#  [Legal time in the Principality will be set, from the date of promulgation
+#   of the present ordinance, to legal time in France....  Consequently, legal
+#   time will be retarded by 9 minutes and 21 seconds.]
+#
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
-Zone	Europe/Monaco	0:29:32 -	LMT	1891 Mar 15
-			0:09:21	-	PMT	1911 Mar 11 # Paris Mean Time
+Zone	Europe/Monaco	0:29:32 -	LMT	1892 Jun  1
+			0:09:21	-	PMT	1911 Mar 29 # Paris Mean Time
 			0:00	France	WE%sT	1945 Sep 16  3:00
 			1:00	France	CE%sT	1977
 			1:00	EU	CE%sT
@@ -2057,7 +2150,7 @@
 # The data entries before 1945 are taken from
 # https://www.staff.science.uu.nl/~gent0113/wettijd/wettijd.htm
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Neth	1916	only	-	May	 1	0:00	1:00	NST	# Netherlands Summer Time
 Rule	Neth	1916	only	-	Oct	 1	0:00	0	AMT	# Amsterdam Mean Time
 Rule	Neth	1917	only	-	Apr	16	2:00s	1:00	NST
@@ -2094,7 +2187,7 @@
 # Norway
 # http://met.no/met/met_lex/q_u/sommertid.html (2004-01) agrees with Shanks &
 # Pottenger.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Norway	1916	only	-	May	22	1:00	1:00	S
 Rule	Norway	1916	only	-	Sep	30	0:00	0	-
 Rule	Norway	1945	only	-	Apr	 2	2:00s	1:00	S
@@ -2163,7 +2256,7 @@
 # The 1919 dates and times can be found in Tygodnik Urzędowy nr 1 (1919-03-20),
 # <http://www.wbc.poznan.pl/publication/32156> pp 1-2.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Poland	1918	1919	-	Sep	16	2:00s	0	-
 Rule	Poland	1919	only	-	Apr	15	2:00s	1:00	S
 Rule	Poland	1944	only	-	Apr	 3	2:00s	1:00	S
@@ -2234,7 +2327,7 @@
 # Guess that the Azores changed to EU rules in 1992 (since that's when Portugal
 # harmonized with EU rules), and that they stayed +0:00 that winter.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 # DSH writes that despite Decree 1,469 (1915), the change to the clocks was not
 # done every year, depending on what Spain did, because of railroad schedules.
 # Go with Shanks & Pottenger.
@@ -2347,7 +2440,7 @@
 # assume that Romania and Moldova switched to EU rules in 1997,
 # the same year as Bulgaria.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Romania	1932	only	-	May	21	 0:00s	1:00	S
 Rule	Romania	1932	1939	-	Oct	Sun>=1	 0:00s	0	-
 Rule	Romania	1933	1939	-	Apr	Sun>=2	 0:00s	1:00	S
@@ -3445,7 +3538,7 @@
 # fallback transition from the next day's 00:59... to 00:00.
 
 # From Michael Deckers (2016-12-15):
-# The Royal Decree of 1900-06-26 quoted by Planesas, online at
+# The Royal Decree of 1900-07-26 quoted by Planesas, online at
 # https://www.boe.es/datos/pdfs/BOE//1900/209/A00383-00384.pdf
 # says in its article 5 (my translation):
 # These dispositions will enter into force beginning with the
@@ -3452,7 +3545,7 @@
 # instant at which, according to the time indicated in article 1,
 # the 1st day of January of 1901 will begin.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Spain	1918	only	-	Apr	15	23:00	1:00	S
 Rule	Spain	1918	1919	-	Oct	 6	24:00s	0	-
 Rule	Spain	1919	only	-	Apr	 6	23:00	1:00	S
@@ -3589,7 +3682,7 @@
 # By the end of the 18th century clocks and watches became commonplace
 # and their performance improved enormously.  Communities began to keep
 # mean time in preference to apparent time - Geneva from 1780 ....
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 # From Whitman (who writes "Midnight?"):
 # Rule	Swiss	1940	only	-	Nov	 2	0:00	1:00	S
 # Rule	Swiss	1940	only	-	Dec	31	0:00	0	-
@@ -3676,7 +3769,7 @@
 # 1853-07-16, though it probably occurred at some other date in Zurich, and
 # legal civil time probably changed at still some other transition date.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Swiss	1941	1942	-	May	Mon>=1	1:00	1:00	S
 Rule	Swiss	1941	1942	-	Oct	Mon>=1	2:00	0	-
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
@@ -3825,7 +3918,7 @@
 # Although Google Translate misfires on that source, it looks like
 # Turkey reversed last month's decision, and so will stay at +03.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Turkey	1916	only	-	May	 1	0:00	1:00	S
 Rule	Turkey	1916	only	-	Oct	 1	0:00	0	-
 Rule	Turkey	1920	only	-	Mar	28	0:00	1:00	S
@@ -3983,7 +4076,7 @@
 			2:00	1:00	EEST	1991 Sep 29  3:00
 			2:00	E-Eur	EE%sT	1995
 			2:00	EU	EE%sT
-# Ruthenia used CET 1990/1991.
+# Transcarpathia used CET 1990/1991.
 # "Uzhhorod" is the transliteration of the Rusyn/Ukrainian pronunciation, but
 # "Uzhgorod" is more common in English.
 Zone Europe/Uzhgorod	1:29:12 -	LMT	1890 Oct
--- contrib/tzdata/leap-seconds.list.orig
+++ contrib/tzdata/leap-seconds.list
@@ -204,10 +204,10 @@
 #	current -- the update time stamp, the data and the name of the file
 #	will not change.
 #
-#	Updated through IERS Bulletin C59
-#	File expires on:  28 December 2020
+#	Updated through IERS Bulletin C60
+#	File expires on:  28 June 2021
 #
-#@	3818102400
+#@	3833827200
 #
 2272060800	10	# 1 Jan 1972
 2287785600	11	# 1 Jul 1972
@@ -252,4 +252,4 @@
 #	the hash line is also ignored in the
 #	computation.
 #
-#h	a1c168ae 27c79a7d 9dddcfc3 bcfe616b 2e2c44ea
+#h 	064356a8 39268b92 76e4d5ef 3e22fae1 0cca529c
--- contrib/tzdata/leapseconds.orig
+++ contrib/tzdata/leapseconds
@@ -68,11 +68,11 @@
 # Any additional leap seconds will come after this.
 # This Expires line is commented out for now,
 # so that pre-2020a zic implementations do not reject this file.
-#Expires 2020	Dec	28	00:00:00
+#Expires 2021	Jun	28	00:00:00
 
 # POSIX timestamps for the data in this file:
 #updated 1467936000 (2016-07-08 00:00:00 UTC)
-#expires 1609113600 (2020-12-28 00:00:00 UTC)
+#expires 1624838400 (2021-06-28 00:00:00 UTC)
 
-#	Updated through IERS Bulletin C59
-#	File expires on:  28 December 2020
+#	Updated through IERS Bulletin C60
+#	File expires on:  28 June 2021
--- contrib/tzdata/leapseconds.awk.orig
+++ contrib/tzdata/leapseconds.awk
@@ -105,8 +105,10 @@
     print ""
     print "# UTC timestamp when this leap second list expires."
     print "# Any additional leap seconds will come after this."
-    print "# This Expires line is commented out for now,"
-    print "# so that pre-2020a zic implementations do not reject this file."
+    if (! EXPIRES_LINE) {
+      print "# This Expires line is commented out for now,"
+      print "# so that pre-2020a zic implementations do not reject this file."
+    }
     printf "%sExpires %.4d\t%s\t%.2d\t%.2d:%.2d:%.2d\n", \
       EXPIRES_LINE ? "" : "#", \
       ss_year, monthabbr[ss_month], ss_mday, ss_hour, ss_min, ss_sec
--- contrib/tzdata/northamerica.orig
+++ contrib/tzdata/northamerica
@@ -170,7 +170,7 @@
 # U.S. government action.  So even though the "US" rules have changed
 # in the latest release, other countries won't be affected.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	US	1918	1919	-	Mar	lastSun	2:00	1:00	D
 Rule	US	1918	1919	-	Oct	lastSun	2:00	0	S
 Rule	US	1942	only	-	Feb	9	2:00	1:00	W # War
@@ -347,7 +347,7 @@
 # Eastern time (i.e., -4:56:01.6) just before the 1883 switch.  Round to the
 # nearest second.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule	NYC	1920	only	-	Mar	lastSun	2:00	1:00	D
 Rule	NYC	1920	only	-	Oct	lastSun	2:00	0	S
 Rule	NYC	1921	1966	-	Apr	lastSun	2:00	1:00	D
@@ -431,7 +431,7 @@
 # The Tennessean 2007-05-11, republished 2015-04-06.
 # https://www.tennessean.com/story/insider/extras/2015/04/06/archives-seigenthaler-for-100-years-the-tennessean-had-it-covered/25348545/
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule	Chicago	1920	only	-	Jun	13	2:00	1:00	D
 Rule	Chicago	1920	1921	-	Oct	lastSun	2:00	0	S
 Rule	Chicago	1921	only	-	Mar	lastSun	2:00	1:00	D
@@ -500,7 +500,7 @@
 # El Paso Times. 2018-10-24 06:40 -06.
 # https://www.elpasotimes.com/story/news/local/el-paso/2018/10/24/el-pasoans-were-time-rebels-fought-stay-mountain-zone/1744509002/
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule	Denver	1920	1921	-	Mar	lastSun	2:00	1:00	D
 Rule	Denver	1920	only	-	Oct	lastSun	2:00	0	S
 Rule	Denver	1921	only	-	May	22	2:00	0	S
@@ -553,7 +553,7 @@
 # https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1501&context=ca_ballot_props
 # https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1636&context=ca_ballot_props
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule	CA	1948	only	-	Mar	14	2:01	1:00	D
 Rule	CA	1949	only	-	Jan	 1	2:00	0	S
 Rule	CA	1950	1966	-	Apr	lastSun	1:00	1:00	D
@@ -911,7 +911,7 @@
 # going to switch from Central to Eastern Time on March 11, 2007....
 # http://www.indystar.com/apps/pbcs.dll/article?AID=/20070207/LOCAL190108/702070524/0/LOCAL
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule Indianapolis 1941	only	-	Jun	22	2:00	1:00	D
 Rule Indianapolis 1941	1954	-	Sep	lastSun	2:00	0	S
 Rule Indianapolis 1946	1954	-	Apr	lastSun	2:00	1:00	D
@@ -930,7 +930,7 @@
 #
 # Eastern Crawford County, Indiana, left its clocks alone in 1974,
 # as well as from 1976 through 2005.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule	Marengo	1951	only	-	Apr	lastSun	2:00	1:00	D
 Rule	Marengo	1951	only	-	Sep	lastSun	2:00	0	S
 Rule	Marengo	1954	1960	-	Apr	lastSun	2:00	1:00	D
@@ -949,7 +949,7 @@
 # Daviess, Dubois, Knox, and Martin Counties, Indiana,
 # switched from eastern to central time in April 2006, then switched back
 # in November 2007.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule Vincennes	1946	only	-	Apr	lastSun	2:00	1:00	D
 Rule Vincennes	1946	only	-	Sep	lastSun	2:00	0	S
 Rule Vincennes	1953	1954	-	Apr	lastSun	2:00	1:00	D
@@ -974,7 +974,7 @@
 # The Indianapolis News, Friday 27 October 1967 states that Perry County
 # returned to CST.  It went again to EST on 27 April 1969, as documented by the
 # Indianapolis star of Saturday 26 April.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule Perry	1955	only	-	May	 1	0:00	1:00	D
 Rule Perry	1955	1960	-	Sep	lastSun	2:00	0	S
 Rule Perry	1956	1963	-	Apr	lastSun	2:00	1:00	D
@@ -991,7 +991,7 @@
 #
 # Pike County, Indiana moved from central to eastern time in 1977,
 # then switched back in 2006, then switched back again in 2007.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule	Pike	1955	only	-	May	 1	0:00	1:00	D
 Rule	Pike	1955	1960	-	Sep	lastSun	2:00	0	S
 Rule	Pike	1956	1964	-	Apr	lastSun	2:00	1:00	D
@@ -1012,7 +1012,7 @@
 # An article on page A3 of the Sunday, 1991-10-27 Washington Post
 # notes that Starke County switched from Central time to Eastern time as of
 # 1991-10-27.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule	Starke	1947	1961	-	Apr	lastSun	2:00	1:00	D
 Rule	Starke	1947	1954	-	Sep	lastSun	2:00	0	S
 Rule	Starke	1955	1956	-	Oct	lastSun	2:00	0	S
@@ -1029,7 +1029,7 @@
 #
 # Pulaski County, Indiana, switched from eastern to central time in
 # April 2006 and then switched back in March 2007.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule	Pulaski	1946	1960	-	Apr	lastSun	2:00	1:00	D
 Rule	Pulaski	1946	1954	-	Sep	lastSun	2:00	0	S
 Rule	Pulaski	1955	1956	-	Oct	lastSun	2:00	0	S
@@ -1071,7 +1071,7 @@
 #
 # Part of Kentucky left its clocks alone in 1974.
 # This also includes Clark, Floyd, and Harrison counties in Indiana.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule Louisville	1921	only	-	May	1	2:00	1:00	D
 Rule Louisville	1921	only	-	Sep	1	2:00	0	S
 Rule Louisville	1941	only	-	Apr	lastSun	2:00	1:00	D
@@ -1185,7 +1185,7 @@
 # election Michigan voters narrowly repealed DST, effective 1969.
 #
 # Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule	Detroit	1948	only	-	Apr	lastSun	2:00	1:00	D
 Rule	Detroit	1948	only	-	Sep	lastSun	2:00	0	S
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
@@ -1202,7 +1202,7 @@
 #
 # Dickinson, Gogebic, Iron, and Menominee Counties, Michigan,
 # switched from EST to CST/CDT in 1973.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
 Rule Menominee	1946	only	-	Apr	lastSun	2:00	1:00	D
 Rule Menominee	1946	only	-	Sep	lastSun	2:00	0	S
 Rule Menominee	1966	only	-	Apr	lastSun	2:00	1:00	D
@@ -1372,7 +1372,7 @@
 # Oct 31, to Oct 27, 1918 (and Sunday is a more likely transition day
 # than Thursday) in all Canadian rulesets.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Canada	1918	only	-	Apr	14	2:00	1:00	D
 Rule	Canada	1918	only	-	Oct	27	2:00	0	S
 Rule	Canada	1942	only	-	Feb	 9	2:00	1:00	W # War
@@ -1395,7 +1395,7 @@
 # that follows the rules is the southeast corner, including Port Hope
 # Simpson and Mary's Harbour, but excluding, say, Black Tickle.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	StJohns	1917	only	-	Apr	 8	2:00	1:00	D
 Rule	StJohns	1917	only	-	Sep	17	2:00	0	S
 # Whitman gives 1919 Apr 5 and 1920 Apr 5; go with Shanks & Pottenger.
@@ -1497,7 +1497,7 @@
 # bill say that it is "accommodating the customs and practices" of those
 # regions, which suggests that they have always been in-line with Halifax.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Halifax	1916	only	-	Apr	 1	0:00	1:00	D
 Rule	Halifax	1916	only	-	Oct	 1	0:00	0	S
 Rule	Halifax	1920	only	-	May	 9	0:00	1:00	D
@@ -1563,7 +1563,7 @@
 # clear that this was the case since at least 1993.
 # For now, assume it started in 1993.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Moncton	1933	1935	-	Jun	Sun>=8	1:00	1:00	D
 Rule	Moncton	1933	1935	-	Sep	Sun>=8	1:00	0	S
 Rule	Moncton	1936	1938	-	Jun	Sun>=1	1:00	1:00	D
@@ -1772,7 +1772,7 @@
 #   With some exceptions, the use of daylight saving may be said to be limited
 # to those cities and towns lying between Quebec city and Windsor, Ont.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Toronto	1919	only	-	Mar	30	23:30	1:00	D
 Rule	Toronto	1919	only	-	Oct	26	0:00	0	S
 Rule	Toronto	1920	only	-	May	 2	2:00	1:00	D
@@ -1870,7 +1870,7 @@
 # starting 1966.  Since 02:00s is clearly correct for 1967 on, assume
 # it was also 02:00s in 1966.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Winn	1916	only	-	Apr	23	0:00	1:00	D
 Rule	Winn	1916	only	-	Sep	17	0:00	0	S
 Rule	Winn	1918	only	-	Apr	14	2:00	1:00	D
@@ -1961,7 +1961,7 @@
 # long and rather painful to read.
 # http://www.qp.gov.sk.ca/documents/English/Statutes/Statutes/T14.pdf
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Regina	1918	only	-	Apr	14	2:00	1:00	D
 Rule	Regina	1918	only	-	Oct	27	2:00	0	S
 Rule	Regina	1930	1934	-	May	Sun>=1	0:00	1:00	D
@@ -2011,7 +2011,7 @@
 # Boyer JP. Forcing Choice: The Risky Reward of Referendums. Dundum. 2017.
 # ISBN 978-1459739123.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Edm	1918	1919	-	Apr	Sun>=8	2:00	1:00	D
 Rule	Edm	1918	only	-	Oct	27	2:00	0	S
 Rule	Edm	1919	only	-	May	27	2:00	0	S
@@ -2120,7 +2120,7 @@
 # https://searcharchives.vancouver.ca/daylight-saving-1918-starts-again-july-7-1941-start-d-s-sept-27-end-of-d-s-1941
 # We have no further details, so omit them for now.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Vanc	1918	only	-	Apr	14	2:00	1:00	D
 Rule	Vanc	1918	only	-	Oct	27	2:00	0	S
 Rule	Vanc	1942	only	-	Feb	 9	2:00	1:00	W # War
@@ -2449,7 +2449,19 @@
 # consistency with nearby Dawson Creek, Creston, and Fort Nelson.
 # https://yukon.ca/en/news/yukon-end-seasonal-time-change
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# From Andrew G. Smith (2020-09-24):
+# Yukon has completed its regulatory change to be on UTC -7 year-round....
+# http://www.gov.yk.ca/legislation/regs/oic2020_125.pdf
+# What we have done is re-defined Yukon Standard Time, as we are
+# authorized to do under section 33 of our Interpretation Act:
+# http://www.gov.yk.ca/legislation/acts/interpretation_c.pdf
+#
+# From Paul Eggert (2020-09-24):
+# tzdb uses the obsolete YST abbreviation for standard time in Yukon through
+# about 1970, and uses PST for standard time in Yukon since then.  Consistent
+# with that, use MST for -07, the new standard time in Yukon effective Nov. 1.
+
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	NT_YK	1918	only	-	Apr	14	2:00	1:00	D
 Rule	NT_YK	1918	only	-	Oct	27	2:00	0	S
 Rule	NT_YK	1919	only	-	May	25	2:00	1:00	D
@@ -2503,12 +2515,12 @@
 Zone America/Whitehorse	-9:00:12 -	LMT	1900 Aug 20
 			-9:00	NT_YK	Y%sT	1967 May 28  0:00
 			-8:00	NT_YK	P%sT	1980
-			-8:00	Canada	P%sT	2020 Mar  8  2:00
+			-8:00	Canada	P%sT	2020 Nov  1
 			-7:00	-	MST
 Zone America/Dawson	-9:17:40 -	LMT	1900 Aug 20
 			-9:00	NT_YK	Y%sT	1973 Oct 28  0:00
 			-8:00	NT_YK	P%sT	1980
-			-8:00	Canada	P%sT	2020 Mar  8  2:00
+			-8:00	Canada	P%sT	2020 Nov  1
 			-7:00	-	MST
 
 
@@ -2723,7 +2735,7 @@
 # 5- The islands, reefs and keys shall take their timezone from the
 #    longitude they are located at.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Mexico	1939	only	-	Feb	5	0:00	1:00	D
 Rule	Mexico	1939	only	-	Jun	25	0:00	0	S
 Rule	Mexico	1940	only	-	Dec	9	0:00	1:00	D
@@ -2928,7 +2940,7 @@
 # rules to sync with the U.S. starting in 2007....
 # http://www.jonesbahamas.com/?c=45&a=10412
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Bahamas	1964	1975	-	Oct	lastSun	2:00	0	S
 Rule	Bahamas	1964	1975	-	Apr	lastSun	2:00	1:00	D
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
@@ -2940,7 +2952,7 @@
 
 # For 1899 Milne gives -3:58:29.2; round that.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Barb	1977	only	-	Jun	12	2:00	1:00	D
 Rule	Barb	1977	1978	-	Oct	Sun>=1	2:00	0	S
 Rule	Barb	1978	1980	-	Apr	Sun>=15	2:00	1:00	D
@@ -2953,7 +2965,7 @@
 
 # Belize
 # Whitman entirely disagrees with Shanks; go with Shanks & Pottenger.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Belize	1918	1942	-	Oct	Sun>=2	0:00	0:30	-0530
 Rule	Belize	1919	1943	-	Feb	Sun>=9	0:00	0	CST
 Rule	Belize	1973	only	-	Dec	 5	0:00	1:00	CDT
@@ -2990,7 +3002,7 @@
 
 # Milne gives -5:36:13.3 as San José mean time; round to nearest.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	CR	1979	1980	-	Feb	lastSun	0:00	1:00	D
 Rule	CR	1979	1980	-	Jun	Sun>=1	0:00	0	S
 Rule	CR	1991	1992	-	Jan	Sat>=15	0:00	1:00	D
@@ -3164,7 +3176,7 @@
 # From Paul Eggert (2012-11-03):
 # For now, assume the future rule is first Sunday in November.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Cuba	1928	only	-	Jun	10	0:00	1:00	D
 Rule	Cuba	1928	only	-	Oct	10	0:00	0	S
 Rule	Cuba	1940	1942	-	Jun	Sun>=1	0:00	1:00	D
@@ -3233,7 +3245,7 @@
 # decided to revert.
 
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	DR	1966	only	-	Oct	30	0:00	1:00	EDT
 Rule	DR	1967	only	-	Feb	28	0:00	0	EST
 Rule	DR	1969	1973	-	Oct	lastSun	0:00	0:30	-0430
@@ -3250,7 +3262,7 @@
 
 # El Salvador
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Salv	1987	1988	-	May	Sun>=1	0:00	1:00	D
 Rule	Salv	1987	1988	-	Sep	lastSun	0:00	0	S
 # There are too many San Salvadors elsewhere, so use America/El_Salvador
@@ -3279,7 +3291,7 @@
 # (2006-04-19), says DST ends at 24:00.  See
 # http://www.sieca.org.gt/Sitio_publico/Energeticos/Doc/Medidas/Cambio_Horario_Nac_190406.pdf
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Guat	1973	only	-	Nov	25	0:00	1:00	D
 Rule	Guat	1974	only	-	Feb	24	0:00	0	S
 Rule	Guat	1983	only	-	May	21	0:00	1:00	D
@@ -3360,7 +3372,7 @@
 # I have not been able to find a more authoritative source:
 # https://www.haitilibre.com/en/news-20319-haiti-notices-time-change-in-haiti.html
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Haiti	1983	only	-	May	8	0:00	1:00	D
 Rule	Haiti	1984	1987	-	Apr	lastSun	0:00	1:00	D
 Rule	Haiti	1983	1987	-	Oct	lastSun	0:00	0	S
@@ -3408,7 +3420,7 @@
 # http://www.laprensahn.com/pais_nota.php?id04962=7386
 # So it seems that Honduras will not enter DST this year....
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Hond	1987	1988	-	May	Sun>=1	0:00	1:00	D
 Rule	Hond	1987	1988	-	Sep	lastSun	0:00	0	S
 Rule	Hond	2006	only	-	May	Sun>=1	0:00	1:00	D
@@ -3499,7 +3511,7 @@
 # The natural sun time is restored in all the national territory, in that the
 # time is returned one hour at 01:00 am of October 1 of 2006.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Nic	1979	1980	-	Mar	Sun>=16	0:00	1:00	D
 Rule	Nic	1979	1980	-	Jun	Mon>=23	0:00	0	S
 Rule	Nic	2005	only	-	Apr	10	0:00	1:00	D
--- contrib/tzdata/southamerica.orig
+++ contrib/tzdata/southamerica
@@ -48,7 +48,7 @@
 # I am sending modifications to the Argentine time zone table...
 # AR was chosen because they are the ISO letters that represent Argentina.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Arg	1930	only	-	Dec	 1	0:00	1:00	-
 Rule	Arg	1931	only	-	Apr	 1	0:00	0	-
 Rule	Arg	1931	only	-	Oct	15	0:00	1:00	-
@@ -769,7 +769,7 @@
 # From Paul Eggert (2013-10-17):
 # For now, assume western Amazonas will change as well.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 # Decree 20,466 <http://pcdsh01.on.br/HV20466.htm> (1931-10-01)
 # Decree 21,896 <http://pcdsh01.on.br/HV21896.htm> (1932-01-10)
 Rule	Brazil	1931	only	-	Oct	 3	11:00	1:00	-
@@ -1258,7 +1258,7 @@
 # For now, assume that they will not revert,
 # since they have extended the expiration date once already.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Chile	1927	1931	-	Sep	 1	0:00	1:00	-
 Rule	Chile	1928	1932	-	Apr	 1	0:00	0	-
 Rule	Chile	1968	only	-	Nov	 3	4:00u	1:00	-
@@ -1358,7 +1358,7 @@
 # Milne gives 4:56:16.4 for Bogotá time in 1899; round to nearest.  He writes,
 # "A variation of fifteen minutes in the public clocks of Bogota is not rare."
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	CO	1992	only	-	May	 3	0:00	1:00	-
 Rule	CO	1993	only	-	Apr	 4	0:00	0	-
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
@@ -1418,7 +1418,7 @@
 # (Not one step back), the clocks went back in 1993 and the experiment was not
 # repeated.  For now, assume transitions were at 00:00 local time country-wide.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Ecuador	1992	only	-	Nov	28	0:00	1:00	-
 Rule	Ecuador	1993	only	-	Feb	 5	0:00	0	-
 #
@@ -1512,7 +1512,7 @@
 # For now we will assume permanent -03 for the Falklands
 # until advised differently (to apply for 2012 and beyond, after the 2011
 # experiment was apparently successful.)
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Falk	1937	1938	-	Sep	lastSun	0:00	1:00	-
 Rule	Falk	1938	1942	-	Mar	Sun>=19	0:00	0	-
 Rule	Falk	1939	only	-	Oct	1	0:00	1:00	-
@@ -1558,7 +1558,7 @@
 # No time of the day is established for the adjustment, so people normally
 # adjust their clocks at 0 hour of the given dates.
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Para	1975	1988	-	Oct	 1	0:00	1:00	-
 Rule	Para	1975	1978	-	Mar	 1	0:00	0	-
 Rule	Para	1979	1991	-	Apr	 1	0:00	0	-
@@ -1651,7 +1651,7 @@
 # From Paul Eggert (2006-03-22):
 # Shanks & Pottenger don't have this transition.  Assume 1986 was like 1987.
 
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Peru	1938	only	-	Jan	 1	0:00	1:00	-
 Rule	Peru	1938	only	-	Apr	 1	0:00	0	-
 Rule	Peru	1938	1939	-	Sep	lastSun	0:00	1:00	-
@@ -1747,7 +1747,7 @@
 # https://www.impo.com.uy/diariooficial/1926/03/10/2
 # https://www.impo.com.uy/diariooficial/1926/03/18/2
 #
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Uruguay	1923	1925	-	Oct	 1	 0:00	0:30	-
 Rule	Uruguay	1924	1926	-	Apr	 1	 0:00	0	-
 # From Tim Parenti (2018-02-15):
--- contrib/tzdata/theory.html.orig
+++ contrib/tzdata/theory.html
@@ -33,7 +33,7 @@
 The <a
 href="https://www.iana.org/time-zones"><code><abbr>tz</abbr></code>
 database</a> attempts to record the history and predicted future of
-all computer-based clocks that track civil time.
+civil time scales.
 It organizes <a href="tz-link.html">time zone and daylight saving time
 data</a> by partitioning the world into <a
 href="https://en.wikipedia.org/wiki/List_of_tz_database_time_zones"><dfn>timezones</dfn></a>
@@ -115,17 +115,15 @@
 Inexperienced users are not expected to select these names unaided.
 Distributors should provide documentation and/or a simple selection
 interface that explains each name via a map or via descriptive text like
-"Ruthenia" instead of the timezone name "<code>Europe/Uzhgorod</code>".
+"Czech Republic" instead of the timezone name "<code>Europe/Prague</code>".
 If geolocation information is available, a selection interface can
 locate the user on a timezone map or prioritize names that are
 geographically close. For an example selection interface, see the
 <code>tzselect</code> program in the <code><abbr>tz</abbr></code> code.
-The <a href="http://cldr.unicode.org/">Unicode Common Locale Data
+The <a href="http://cldr.unicode.org">Unicode Common Locale Data
 Repository</a> contains data that may be useful for other selection
-interfaces; it maps timezone names like <code>Europe/Uzhgorod</code>
-to CLDR names like <code>uauzh</code> which are in turn mapped to
-locale-dependent strings like "Uzhhorod", "Ungvár", "Ужгород", and
-"乌日哥罗德".
+interfaces; it maps timezone names like <code>Europe/Prague</code> to
+locale-dependent strings like "Prague", "Praha", "Прага", and "布拉格".
 </p>
 
 <p>
@@ -693,6 +691,14 @@
     <code><abbr>tz</abbr></code> database requires.
   </li>
   <li>
+    The <code><abbr>tz</abbr></code> database cannot represent stopped clocks.
+    However, on 1911-03-11 at 00:00, some public-facing French clocks
+    were changed by stopping them for a few minutes to effect a transition.
+    The <code><abbr>tz</abbr></code> database models this via a
+    backward transition; the relevant French legislation does not
+    specify exactly how the transition was to occur.
+  </li>
+  <li>
     Sometimes historical timekeeping was specified more precisely
     than what the <code><abbr>tz</abbr></code> code can handle.
     For example, from 1909 to 1937 <a
@@ -1321,17 +1327,21 @@
 <section>
   <h2 id="planets">Time and time zones on other planets</h2>
 <p>
-Some people's work schedules
-use <a href="https://en.wikipedia.org/wiki/Timekeeping_on_Mars">Mars time</a>.
+Some people's work schedules have used
+<a href="https://en.wikipedia.org/wiki/Timekeeping_on_Mars">Mars time</a>.
 Jet Propulsion Laboratory (JPL) coordinators kept Mars time on
 and off during the
 <a href="https://en.wikipedia.org/wiki/Mars_Pathfinder">Mars
-Pathfinder</a> mission.
+Pathfinder</a> mission (1997).
 Some of their family members also adapted to Mars time.
 Dozens of special Mars watches were built for JPL workers who kept
-Mars time during the Mars Exploration Rovers mission (2004).
-These timepieces look like normal Seikos and Citizens but use Mars
-seconds rather than terrestrial seconds.
+Mars time during the
+<a href="https://en.wikipedia.org/wiki/Mars_Exploration_Rover">Mars
+Exploration Rovers (MER)</a> mission (2004&ndash;2018).
+These timepieces looked like normal Seikos and Citizens but were adjusted
+to use Mars seconds rather than terrestrial seconds, although
+unfortunately the adjusted watches were unreliable and appear to have
+had only limited use.
 </p>
 
 <p>
@@ -1339,6 +1349,8 @@
 about 24 hours 39 minutes 35.244 seconds in terrestrial time.
 It is divided into a conventional 24-hour clock, so each Mars second
 equals about 1.02749125 terrestrial seconds.
+(One MER worker noted, "If I am working Mars hours, and Mars hours are
+2.5% more than Earth hours, shouldn't I get an extra 2.5% pay raise?")
 </p>
 
 <p>
@@ -1354,12 +1366,12 @@
 <p>
 Each landed mission on Mars has adopted a different reference for
 solar timekeeping, so there is no real standard for Mars time zones.
-For example, the
-<a href="https://en.wikipedia.org/wiki/Mars_Exploration_Rover">Mars
-Exploration Rover</a> project (2004) defined two time zones "Local
+For example, the MER mission defined two time zones "Local
 Solar Time A" and "Local Solar Time B" for its two missions, each zone
 designed so that its time equals local true solar time at
 approximately the middle of the nominal mission.
+The A and B zones differ enough so that an MER worker assigned to
+the A zone might suffer "Mars lag" when switching to work in the B zone.
 Such a "time zone" is not particularly suited for any application
 other than the mission itself.
 </p>
@@ -1408,9 +1420,14 @@
     Michael Allison and Robert Schmunk,
     "<a href="https://www.giss.nasa.gov/tools/mars24/help/notes.html">Technical
       Notes on Mars Solar Time as Adopted by the Mars24 Sunclock</a>"
-    (2018-12-13).
+    (2020-03-08).
   </li>
   <li>
+    Zara Mirmalek,
+    <em><a href="https://mitpress.mit.edu/books/making-time-mars">Making
+	Time on Mars</a></em>, MIT Press (March 2020), ISBN 978-0262043854.
+  </li>
+  <li>
     Jia-Rui Chong,
     "<a href="https://www.latimes.com/archives/la-xpm-2004-jan-14-sci-marstime14-story.html">Workdays
     Fit for a Martian</a>", <cite>Los Angeles Times</cite>
--- contrib/tzdata/version.orig
+++ contrib/tzdata/version
@@ -1 +1 @@
-2020a
+2020d
--- contrib/tzdata/ziguard.awk.orig
+++ contrib/tzdata/ziguard.awk
@@ -3,7 +3,14 @@
 # Contributed by Paul Eggert.  This file is in the public domain.
 
 # This is not a general-purpose converter; it is designed for current tzdata.
+# It just converts from current source to main, vanguard, and rearguard forms.
+# Although it might be nice for it to be idempotent, or to be useful
+# for converting back and forth between vanguard and rearguard formats,
+# it does not do these nonessential tasks now.
 #
+# Although main and vanguard forms are currently equivalent,
+# this need not always be the case.
+#
 # When converting to vanguard form, the output can use negative SAVE
 # values.
 #
@@ -28,7 +35,7 @@
   in_comment = /^#/
   uncomment = comment_out = 0
 
-  # If the line should differ due to Czechoslovakia using negative SAVE values,
+  # If this line should differ due to Czechoslovakia using negative SAVE values,
   # uncomment the desired version and comment out the undesired one.
   if (zone == "Europe/Prague" && /1947 Feb 23/) {
     if (($(in_comment + 2) != "-") == vanguard) {
--- contrib/tzdata/zishrink.awk.orig
+++ contrib/tzdata/zishrink.awk
@@ -166,9 +166,6 @@
   ruleline = sub(/^Rule /, "R ", line)
   zoneline = sub(/^Zone /, "Z ", line)
 
-  # SystemV rules are not needed.
-  if (line ~ /^R SystemV /) return
-
   # Replace FooAsia rules with the same rules without "Asia", as they
   # are duplicates.
   if (match(line, /[^ ]Asia /)) {
@@ -275,7 +272,6 @@
   default_dep["factory"] = 1
   default_dep["northamerica"] = 1
   default_dep["southamerica"] = 1
-  default_dep["systemv"] = 1
   default_dep["ziguard.awk"] = 1
   default_dep["zishrink.awk"] = 1
 
--- contrib/tzdata/zoneinfo2tdf.pl.orig
+++ contrib/tzdata/zoneinfo2tdf.pl
@@ -38,7 +38,7 @@
     }
     $contZone = $fields[1] if @fields > 5;
   } elsif ($type eq 'rule') {
-    # Rule  NAME  FROM  TO  TYPE  IN  ON  AT  SAVE  LETTER/S
+    # Rule  NAME  FROM  TO  -  IN  ON  AT  SAVE  LETTER/S
     @fields == 10 or warn "bad rule line";
   } elsif ($type eq 'link') {
     # Link  TARGET  LINK-NAME
